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PubMed1975

Fluorescent antibody localization of the vitamin D-dependent calcium-binding protein in the oviduct of the laying hen.

Fluorescein isothiocyanate-conjugated sheep antirabbit gamma-globulin was used in the indirect fluorescent antibody technique to localize the vitamin D-dependent calcium-binding protein (CaBP) in the shell gland of the laying hen. Intense specific fluorescence, indicative of the presence of CaBP, was found only in the tubular gland cells and not in the surface epithelium. CaBP was primarily associated with the luminal surface and other cell boundaries, and in lesser concentrations within the cells except for occasional intracellular regions of high concentration. The magnum, isthmus and vagina were essentially negative. Since the concentrations of intestinal CaBP is highly and directly correlated with the efficiency of calcium absorption, the present results suggest that the tubular gland cells might have a primary role in the transport of calcium associated with egg shell formation.

Animals↗
PubMed1991

Histochemical studies on rectal mucosa in active intestinal schistosomiasis.

Thirty patients suffering from active intestinal S. mansoni infection, were classified into 3 groups. The first group: 13 cases with early active intestinal schistosomiasis without hepatosplenomegaly. The second group: 11 cases with hepatosplenomegaly and the third group: 6 cases with splenomegaly and ascites. Also 10 normal individuals were included as a normal control group. Histopathological examination of rectal mucosa showed hyperaemia with extravasation of blood in early cases and granulomatous lesions in the second group with hepatosplenomegaly. The structural changes were severe in the late ascitic group. In this group the rectal mucosal glands showed distorted irregular tubular branching in addition to the granulomatous and the fibrous reactions. Histochemical studies including periodic acid schiff, alkaline phosphatase and acetyl cholinestrase reactions were done. Using the periodic acid shiff stain, the goblet cells showed strong reaction for neutral mucin in cases of group I (early cases) and group II (late hepatosplenomegalic cases). In group III (late ascitic cases) the goblet cells were faintly stained. A notable difference was observed between the lightly and heavily infected patients of this group. No alkaline phosphatase reactivity could be identified in rectal crypts of patients and controls. Alkaline phosphatase reactivity was sharply localised in S. mansoni egg shell. There was obvious decrease in the acetyl cholinesterase stained nerve fibres in the rectal mucosa of all studied patients. The decrease was more in chronic and heavily infected cases rather than in the acute and lightly infected ones.

Adolescent↗
PubMedDate not supplied

Prevention and treatment of head lice in children.

Head louse infestations (pediculosis) are prevalent worldwide. In developed countries, the infestation rate of 4- to 13-year-old children remains high despite preventive efforts. This is due to the existence of numerous ineffective pediculicides, the incorrect use of the effective agents, toxicological concerns and the development of louse strains resistant to insecticides. One of the most effective tools for the prevention and control of lice is the louse comb, which should be used regularly for the detection of living lice at an early stage of infestation, and as an accessory to any treatment method to remove living and dead lice. The louse comb can also be used systematically for the treatment of infestations, for confirmation that treatment with pediculicides has been successful, and for the removal of nits (dead eggs or egg shells). Most pediculicides are only partially ovicidal. Therefore, 10 days after beginning treatment with any antilouse product, the scalp of the child should be examined. If no living lice are found, the treatment should be discontinued. If living lice are still present, treatment should be continued with a product containing a different active ingredient. Suffocating agents such as olive, soya, sunflower and corn oils, hair gels and mayonnaise are able to kill a significant number of lice only if they are applied in liberal quantities for more than 12 hours. However, they lubricate the hair and therefore may facilitate combing and removing lice and eggs from the scalp. Nits may remain glued on the hair for at least 6 months, even after a successful treatment, and lead to a false positive diagnosis of louse infestation. If nits are seen on the hair, the child should be examined, but treatment should be initiated only if living lice are found. Formulations containing 5% acetic acid or 8% formic acid, as well as acid shampoos (pH 4.5 to 5.5) and conditioners, in combination with a louse comb, can be helpful for removing nits. There is no conclusive evidence that using essential oils to repel lice is effective. Regular examination of the child's head using a louse comb is the best measure to detect re-infestation at an early stage. Educating caregivers, nurses and teachers about louse biology, epidemiology, prevention and control is of paramount importance. The psychological effect of an infestation with lice is significant and often associated with anxiety and fear. The child should not be made to feel responsible for having lice, or be punished or reprimanded.

Animals↗
PubMed1992

Persistence of eggs and hepatic fibrosis after treatment of Schistosoma mansoni-infected mice.

In 1971 we estimated that Schistosoma mansoni eggs in the tissues of mice were destroyed with an approximate half-life of four weeks. Our present results of five experiments suggest that egg destruction is not as rapid, and no significant destruction of eggs was detected for up to 26 weeks after treatment. However, in these experiments, a mean of 60% of the eggs in intestinal tissues were found in the feces at the time of treatment. In previously reported experiments, only 15% of gut eggs were passed in the feces. We now believe that underestimation of the number of eggs passed in the feces led to an overestimation of the number of eggs destroyed in the tissues. We analyzed liver eggs separately because eggs lost from this site are unaffected by eggs passed in the feces. No significant decrease in liver eggs occurred in the present experiments, but reanalysis of previously published data showed significant egg destruction in the liver in several experiments, although at a much slower rate than previously estimated. However, inspection of the data in the previously published and present experiments does not show a convincing difference in the number of eggs in the liver after treatment. The persistence of egg shells is probably not important in the pathogenesis of disease, but is of concern in calculating worm fecundity. Hepatic collagen levels increased markedly two weeks after treatment and subsequently decreased significantly in some, but not all, experiments.

Analysis of Variance↗
PubMed1976

Histochemical studies on the distribution of alkaline phosphatase, acid phosphatase, 5-nucleotidase and ATPase in various reproductive tissues of certain digenetic trematodes.

Out of other functions performed by vitellaria in digenetic trematodes, their role in the formation of shell globules and shell membrane of the capsule, as well as in the excretion of iron with the help of vitamin C is very important. The present histochemical work shows the localization of certain enzymes in different parts of the reproductive system of ten species of trematodes viz.: Neopronocephalus triangularis Mehra, 1932; Glossimetra orientalis Mehra, 1937; Orientodiscus lobatus Srivastava, 1938; Eumegacetes artemii Mehra, 1935; Ganeo tigrinus mehra et Negi, 1928; Encyclometra caudata Dollfus, 1928; Thapariella udaipurensis Gupta and Sharma, 1970; Paradistomoides indicum Narain et Das, 1929; Patagifer wesleyi Verma, 1936; Proalarioides tropidonotus Vidyarthi, 1937 and indicates their functional significance. The hydrolytic enzymes (alkaline phosphatase, acid phosphatase, 5-nucleotidase and ATPase) are suggestive of their involvement in the uptake of certain nutrients, glycogen and lipoprotein being very significant among others. The four enzymes could also be detected in testes, ovary, uterus, cirrus sac and egg shell. The possible functional significance of each enzyme has been discussed.

Acid Phosphatase↗
PubMed1983

The relationship between body weight loss during an induced molt and postmolt egg production, egg weight, and shell quality in caged layers.

Two trials were conducted to determine the relationship between percent body weight loss (% BWL) during an induced molt and postmolt performance. The molt was induced by fasting and photoperiod manipulation. Four groups with 24, 27, 31, or 35% BWL (Trial 1) or 20, 25, 30, or 35% BWL (Trial 2) were utilized in each trial. Performance was evaluated on the basis of 24 weeks of egg production and determinations of egg weight (EW), specific gravity (SG), and shell weight (SW) conducted during Weeks 8 (Trial 2 only), 18, and 24 following the removal of feed. The 27 and 31% BWL groups of Trial 1 and the 30 and 35% BWL groups of Trial 2 produced significantly more eggs per hen housed than the remaining treatments in their respective trial. Differences in SG and SW at the end of the trial were most pronounced in Trial 1 where the 27 and 21% BWL groups exhibited significantly greater SG and SW at Week 24 than did the 24 or 35% BWL groups. No significant differences occurred for SG at Week 24 of Trial 2, but the 35% BWL group exhibited significantly improved SW when compared to the 25% BWL group with the remaining groups intermediate. The EW was greatest for the 31% BWL and least for the 35% BWL group at 24 weeks in Trial 1 but did not differ in Trial 2. It was concluded that a body weight loss of approximately 27 to 31% produced optimum postmolt performance.

Animals↗
PubMed2001

Effect of supplementary choline on the performance of broiler breeders fed on different energy sources.

1. Laying performance, egg quality, fertility and hatchability, and fat deposition in liver and abdomen were recorded in broiler breeders (29 to 48 weeks of age) fed on diets containing perarl millet (Pennisetum typhoides) (PM), broken rice (BR) or yellow maize (YM) (600 g/kg diet). Constant ratios of metabolisable energy (ME) to other nutrients were maintained in all the diets. Food grade choline chloride (50%) was added to the diets at 3 concentrations (0, 760 and 1,520 mg/kg). Each diet was offered to 3 replicate groups of 15 birds (12 hens and 3 cockerels), maintained in deep litter pens, to provide 1.46 MJ ME/bird/d. 2. Neither the source of energy nor dietary choline content had any influence on hen-d egg production, fertility or hatchability. Food efficiency and egg weight were significantly reduced in BR-fed groups compared to those fed on the other energy sources. 3. The efficiency of energy and protein utilisation increased and liver fat content was decreased significantly by dietary choline supplementation. 4. Haugh unit score, egg shell weight, liver weight and intestinal weight were not influenced by either supplementary choline or the source of energy. However, the yolk colour index was significantly reduced in PM- or BR-fed groups compared to those fed on the maize-based diet. 5. Deposition of abdominal fat was significantly greater in BR-fed birds compared to those fed on the YM-based diet, while liver fat content was significantly greater in the birds fed on the PM-or BR-based diets than those based on YM. Although supplementation of the diet with choline had no influence on abdominal fat deposition, liver fat content was significantly reduced in birds given diet containing 760 mg supplemental choline/kg diet. 6. The present study indicates that PM or BR can be used as principal energy sources in place of YM in broiler breeder diets without affecting egg production, fertility or hatchability. Liver fat content can be reduced by adding choline at 760 mg/kg to diets based on different energy sources.

Abdomen↗
PubMed1991

20-Hydroxyecdysone is required for, and negatively regulates, transcription of Drosophila pupal cuticle protein genes.

Transcripts of ecdysone-dependent genes (EDGs) accumulate in isolated imaginal discs with 8 hr after exposure to a pulse of the steroid hormone 20-hydroxyecdysone (20-HE; 1 microgram/ml for 6 hr) but not in discs cultured in the continuous presence or absence of the hormone. Sequence analyses show that two of the EDGs are members of gene families encoding insect cuticle proteins. We conclude that a third EDG encodes a cuticle protein because the conceptual glycine-rich protein contains sequence motifs similar to those found in insect egg shell proteins and vertebrate cytokeratins and because expression of this gene is limited to tissues that deposit the pupal cuticle. Nuclear run-on assays show that the hormone-dependent expression of each of these EDGs is due to transcriptional regulation. Readdition of hormone to imaginal discs actively synthesizing the EDG messages causes rapid repression of EDG transcription. Thus, 20-HE acts as both a positive and a negative regulator of EDG transcription. Sequences in the promoter regions of two of the EDGs are similar to an ecdysone response element and may play a role in negative regulation.

Amino Acid Sequence↗
PubMed1999

Chorion formation and ultrastructure of the egg of the cat flea (Siphonaptera: Pulicidae).

Oocyte development in adult female cat fleas, Ctenocephalides felis (Bouché), was studied by light and electron microscopy to determine the formation and ultrastructural morphology of the eggshell. As oocytes develop, somatic follicle cells from the lining of the ovariole migrate around the oocytes. The follicle cells produce electron-dense granules that form the vitelline membrane around the developing oocyte. Subsequently, electron-lucent granules containing an electron-dense core (precursors of the chorion) are produced from the rough endoplasmic reticulum that appear as dilated and clear linear clefts in the cytoplasm of the follicle cells. Exocytosis and coalescence of the granules around the oocyte as the follicle cells disintegrate give rise to the chorion. The chorion was found to consist of 4 distinct layers. The external surface of the egg shell consists of a particulate layer approximately 760 nm thick, composed of an electron-lucent layer of widely dispersed granules. Embedded in this layer are electron-dense spheres that project above the surface of this granular layer. Beneath this outermost layer is a band of electron-dense material, consisting of densely packed granules and is half as thick as the outer particulate layer. The 3rd layer consists of relatively thick, weakly laminated chorion, with a felt-like appearance due to a meshwork of microfibrils. Projections of this network of microfibrils form pillars that attach this layer to a thin relatively compact 4th or basal layer. The pillars and the air-filled cavities lying between the 3rd and 4th chorionic layers constitute the chorionic meshwork known as the palisades or trabecular layer that form the major respiratory organ of the eggshell. The trabecular layer is connected to the external environment by means of the lateral and anterior aeroplyes. The vitelline membrane lies between the chorion and oocyte and is a granular, uniform, moderately electron-dense layer measuring approximately 260 nm thick. The micropyle at the posterior of the flea egg consists of a rosette of 50-80 apertures and possesses an internal electron-dense plug between the chorion and the vitelline membrane. An aeropyle at the anterior end of the egg consists of a rosette of 40-50 apertures. An inconspicuous aeropyle appears as a cluster of hexagonal or polygonal-shaped plaques on the lateral surface of the chorion. Each plaque contains 3-8 pores.

Animals↗
PubMed1991

A structural protein that plays an enzymatic role in the eggshell of Drosophila melanogaster.

E.S.P. is responsible for the hardening process of the egg-shell at the end of oogenesis (stage 14B) and constitutes a structural component. By immunoblotting, using polyclonal rabbit anti-HRP antibody and anti-rabbit IgG-HRP or Protein A-1251 as second antibody, one major band with MW 38KD on nitrocellulose filter showed positive reaction. We conclude that the E.S.P. is identical to the S38 chorionic protein. Morphological immunogold staining, using pre-embedding procedure, revealed positive reaction in the innermost chorionic layer (ICL) and the endochorion of the eggshell. In addition, electron probe X-ray microanalysis revealed the existence of 37% calcium (explained since the enzyme is Ca2(+)-activated) and 5% iron (explained due to the fact that it is a haemoprotein).

Animals↗
PubMed2000

Health effects of endocrine-disrupting chemicals on wildlife, with special reference to the European situation.

Many wildlife species may be exposed to biologically active concentrations of endocrine-disrupting chemicals. There is strong evidence obtained from laboratory studies showing the potential of several environmental chemicals to cause endocrine disruption at environmentally realistic exposure levels. In wildlife populations, associations have been reported between reproductive and developmental effects and endocrine-disrupting chemicals. In the aquatic environment, effects have been observed in mammals, birds, reptiles, fish, and mollusks from Europe, North America, and other areas. The observed abnormalities vary from subtle changes to permanent alterations, including disturbed sex differentiation with feminized or masculinized sex organs, changed sexual behavior, and altered immune function. For most reported effects in wildlife, however, the evidence for a causal link with endocrine disruption is weak or nonexisting. Crucial in establishing causal evidence for chemical-induced wildlife effects appeared semifield or laboratory studies using the wildlife species of concern. Impaired reproduction and development causally linked to endocrine-disrupting chemicals are well documented in a number of species and have resulted in local or regional population changes. These include: Masculinization (imposex) in female marine snails by tributyltin, a biocide used in antifouling paints, is probably the clearest case of endocrine disruption caused by an environmental chemical. The dogwhelk is particularly sensitive, and imposex has resulted in decline or extinction of local populations worldwide, including coastal areas all over Europe and the open North Sea. DDE-induced egg-shell thinning in birds has caused severe population declines in a number of raptor species in Europe and North America. Endocrine-disrupting chemicals have adversely affected a variety of fish species. In the vicinity of certain sources (e.g., effluents of water treatment plants) and in the most contaminated areas is this exposure causally linked with the effects on reproductive organs that could have implications for fish populations. However, there is also a more widespread occurrence of endocrine disruption in fish in the U.K., where estrogenic effects have been demonstrated in freshwater systems, in estuaries, and in coastal areas. In mammals, the best evidence comes from the-field studies on Baltic gray and ringed seals, and from the Dutch semifield studies on harbor seals, where both reproduction and immune functions have been impaired by PCBs in the food chain. Reproduction effects resulted in population declines, whereas impaired immune function has likely contributed to the mass mortalities due to morbillivirus infections. Distorted sex organ development and function in alligators has been related to a major pesticide spill into a lake in Florida, U.S.A. The observed estrogenic/antiandrogenic effects in this reptile have been causally linked in experimental studies with alligator eggs to the DDT complex. Although most observed effects currently reported concern heavily polluted areas, endocrine disruption is a potential global problem. This is exemplified by the widespread occurrence of imposex in marine snails and the recent findings of high levels of persistent potential endocrine-disrupting chemicals in several marine mammalian species inhabiting oceanic waters.

Animals↗
PubMed2006

[Biology of gastrointestinal nematodes of ruminants].

The development and survival of free-living stages of gastro-intestinal nematodes of small ruminants are influenced by several abiotic and biotic factors. Within the abiotic factors, most important are the environmental temperature and humidity. They regulate the development of larvae from eggs dispersed on the pasture by the animals faeces. Each parasite species that infect ruminants requires a different time to development, depending on temperature and humidity. Among trichostrongylids, Ostertagia, Teladorsagia and Nematodirus show a strong adaptation to low temperatures. Nematodirus larvae are able to survive to winter inside the egg shell. Temperature and humidity influence the distribution and survival of larvae on pasture. The larval third stage can migrate from faeces to pasture vegetation and they accumulate at the basis of vegetation where stay during the day or in the soil to avoid the desiccation. The forage species affects the migration of larvae on herbage too. Many biological factors contribute to disperse the larvae on the pasture. Dung burying beetles, coprophagous beetles and earthworms can greatly reduce the larvae of some trichostrongylids on pasture. They contribute to the spread of the faecal material on the pasture and allow the larval death as a consequence of drying.

Animal Feed↗
PubMed1976

Effect of citrinin, a mycotoxin produced by Penicillium citrinum, on laying hens and young broiler chicks.

Citrinin fed to mature laying hens at levels of 0, 50, and 250 mug/g. of diet for three weeks had no effect on body weight, feed consumption, egg production, egg weight or egg shell quality. A moderate diarrhea occurring about three days after feeding 250 mug. citrinin/g. of diet was observed. However, the diarrhea subsided once the birds were returned to a normal diet. Young broiler chicks were fed a diet containing either 0, 62.5, 125, 250, or 500 mug. citrinin/g. of diet from hatching to three weeks of age. Body weight was decreased by the 500 mug/g. level whereas all levels of citrinin resulted in enlarged kidneys and an improvement in feed conversion when compared to control values. There was also a slight dose-related increase in liver size. The 250 and 500 mug./g. levels resulted in a dose-related increase in water consumption accompanied by an acute diarrhea. Dietary citrinin had no effect on serum protein, glucose, cholesterol, uric acid, calcium, potassium and sodium concentrations or packed cell volume.

Animal Feed↗
PubMed1992

Protein-DNA associations in a gender-specific gene of Schistosoma mansoni: characterization by UV cross-linking, DNase I footprinting and band shift assays.

Protein extracts obtained from male and female schistosomes were incubated with a gender-specific gene, F-10, transcribed only in adult females and encoding a major egg-shell protein. The protein/DNA interaction was measured using the band shift, DNase-I-footprinting and UV cross-linking techniques. The results showed a clear band shift when a 302 bp restriction fragment containing the 3' end of the gene was incubated with either female or male proteins. This fragment also contained a putative steroid hormone regulatory element (HRE). In contrast, only the male proteins produced a shift with the 495 bp fragment corresponding to the middle region of the gene. DNase I footprinting showed that proteins from males and females interacted with the F-10 gene by binding to multiple adjacent sites along the DNA, thus generating relatively long protected fragments of approximately 100 bp. This result suggested that the adjacent binding of several moles of protein occurred at the 5' end of the gene. UV cross-linking between schistosome proteins and a 21 bp synthetic oligonucleotide containing the F-10 HRE, evidenced proteins having MWS of 30, 45 and 65 kDa. These proteins are presumably involved in the regulation of transcription of the F-10 gene.

Animals↗
PubMed1998

Recovery and refining of Au by gold-cyanide ion biosorption using animal fibrous proteins.

Animal fibrous proteins (AFPs) such as egg-shell membrane (ESM), chicken feather (CF), wool, silk, or elastin are an intricate network of stable and water-insoluble fibers with high surface area and are abundant bioresources. Every AFP tested was found to accumulate gold-cyanide ion from aqueous solutions in high yield, depending on pH and some other parameters. Gold-cyanide ion is adsorbed by AFP at low pH range, with maximum binding observed at approx pH 2.0. Under the certain conditions, gold-cyanide ion was accumulated up to 8.6, 7.1, 9.8, 2.4, and 3.9% of dry weight on ESM, CF, wool, silk, and elastin, respectively. In the case of ESM, it was found that ESM removed gold-cyanide ion almost quantitatively and almost all the gold uptake by ESM was easily desorbed with 0.1 M NaOH. ESM can be used repeatedly for the process of gold adsorption-desorption. The gold-biosorptive capacity of ESM that was chemically modified with glutaraldehyde was higher than that of control. In column procedure, ESM packed on column removed gold-cyanide ion from the dilute aqueous solution to extremely low concentrations (nondetectable concentration of below 1 ppb).

Adsorption↗
PubMed1975

Influence of hormonal extracts on hens producing eggs with non-calcified or partially calcified shells and factors associated with this condition.

1. Daily injection of hypothalameal extract (HE) and adenohypophyseal extract (AE) into hens aged 56 or 67 weeks for 14 d did not significantly influence the production of shell-less (SL) or ultra-thin-shell (UTS) eggs. 2. The injection of HE significantly increased hard-shell (HS) egg production in the younger hens. 3. Neither AE nor HE affected egg weight, serum calcium, gain in body weight or food consumption. 4. In a third experiment hens selected for poor egg production laid at a rate of 58% of which 36% were SL, 29% UTS and 35% HS eggs. Whereas the production rate of the good layers was 65% of which 1-4% were SL and 1-4% were UTS eggs. 5. Specific gravity of HS eggs, serum calcium, weight of ovary, oviduct, or adenohypophysis did not differ between good and poor layers. 6. Since SL and UTS eggs are easily overlooked the decrease in egg production with age may be as great as indicated by normal production records; the problem may be concerned more with the mechanism of shell formation.

Animals↗
PubMed1996

Maternal effect of low temperature on handedness determination in C. elegans embryos.

C. elegans embryos, larvae, and adults exhibit several left-right asymmetries with an invariant dextral handedness, which first becomes evident in the embryo at the 6-cell stage. Reversed (sinistral) handedness was not observed among > 10,000 N2 adults reared at 16 degrees C or 20 degrees C under standard conditions. However, among the progeny of adults reproducing at 10 degrees C, the frequency of animals with sinistral handedness was increased to approximately 0.5%. Cold pulse experiments indicated that the critical period for this increase was in early oogenesis, several hours before the first appearance of left-right asymmetry in the embryo. Hermaphrodites reared at 10 degrees C and mated with males reared at 20 degrees C produced sinistral outcross as well as sinistral self-progeny, indicating that the low temperature effect on oocytes was sufficient to cause reversals. Increased frequency of reversal was also observed among animals developed from embryos lacking the egg shell. Possible mechanisms for the control of embryonic handedness are discussed in the context of these results, including the hypothesis that handedness could be dictated by the chirality of a gametic component.

Animals↗
PubMed1991

Handed asymmetry, handedness reversal and mechanisms of cell fate determination in nematode embryos.

Embryos of the nematode Caenorhabditis elegans exhibit left-right asymmetry with an invariant handedness. The embryonic cell lineage is asymmetrical: although the animal is generally bilaterally symmetrical with only a few left-right asymmetries, many of its contralaterally analogous cells arise via different lineages on the two sides of the embryo. Larvae and adults also exhibit left-right asymmetries with a handedness that is normally invariant. The frequency of animals with opposite handedness was increased among the progeny of adults exposed to the mutagen ethyl methanesulphonate and among animals that developed from embryos treated in early cleavage with chitinase to destroy the egg shell. Reversal of embryonic handedness was accomplished directly by micromanipulation at the 6-cell stage, resulting in mirror-image but otherwise normal development into healthy, fertile animals with all the usual left-right asymmetries reversed. This demonstrates that (1) the handedness of cell positions in the 6-cell embryo dictates handedness throughout development; (2) at this stage the pair of anterior blastomeres on the right is equivalent to the pair on the left; and (3) the extensive differences in fates of lineally homologous cells on the two sides of the animal must be dictated by cellular interactions, most of which are likely to occur early in embryogenesis and appear to have been conserved in widely diverged nematode species.

Animals↗