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At least 127 records · Page 7Linked to original sources
PubMed1995

DNA fingerprinting in captive population of the endangered Siberian crane (Grus leucogeranus).

DNA fingerprinting was used to estimate genetic diversity within the endangered Siberian crane (Grus leucogeranus) captive population consisting of several dozens of founders originating from the two wild populations of eastern and western Siberia. Similarity and difference among captive individuals were demonstrated by the unweighted pair-group (UPGMA) clustering procedure. Quantitative characteristics of the eastern and western captive population groups such as average percentage differences (APD) and heterozygosity showed a high extent of genetic variability of 77.9-79.3% and heterozygosity of 0.85-0.72 within each group. Genetic heterogeneity of the captive population structure observed here provides guidelines for management of the species gene pool in captivity. These data also indicate that monitoring of genetic diversity through DNA fingerprinting can facilitate the efforts of Siberian crane management and restoration.

Animals↗
PubMed1997

Minisatellite DNA markers reveal hybridisation between the endangered black robin and tomtit.

We have used multilocus minisatellite DNA profiling to assess genetic variation in the endangered and highly inbred black robins and the closely related tomtits. These species are restricted to wild populations on the Chatham Islands, off the east coast of New Zealand. DNA profiles revealed a remarkable degree of genetic similarity among black robins, as well as among the tomtits sampled, although the typical profiles of these two species were clearly distinct. The parentage of two putative hybrid chicks and one putative hybrid adult was established for a 'black robin' adult male and an adult tomtit female which were found nesting together. The 'black robin' male, despite being morphologically a typical black robin, was found to possess a number of minisatellite-containing restriction fragments not recorded from the black robin population (n = 103). These fragments were however detected in tomtits. Consequently, this bird appeared to be an F1 hybrid and his three offspring were F2 hybrids. Mitochondrial DNA sequencing of members of this family showed that the 'black robin' male had cytochrome b and 16S of black robin, rather than tomtit, haplotypes. This indicates that the black robin adult male hybrid was the result of a black robin female mating with a tomtit male. These findings are particularly important since tomtits had been used as cross-foster parents for black robins, as part of an earlier conservation recovery program. The existence of any hybrids thus detected would have important implications for cross-fostering programs generally, since may such programs are now being implemented in conservation programs worldwide.

Amino Acid Sequence↗
PubMed2002

Glochidium metamorphosis in the endangered freshwater mussel Margaritifera auricularia (Spengler, 1793): a histological and scanning electron microscopy study.

The metamorphosis of the glochidium of the critically endangered Margaritifera auricularia in the gills of a host is studied here for the first time. Siberian sturgeon, Acipenser baeri, were infected with glochidia and regularly inspected using scanning and optical microscopy. The mature glochidia immediately attach to the epithelium of the sturgeon gill filaments, piercing the secondary lamellae and the connective tissues, blood cells, and vessels within the lamellae. Once the epithelium is pierced, overlapping host lamellae cover the glochidium and form a cyst. Metamorphosis takes place inside the cyst. Sixteen days after infection the glochidium becomes spherical in shape and the larval muscle is reabsorbed. The two adductor muscles of the juvenile are observed 34 days after infection at 16-20 degrees C. Metamorphosis is complete in approximately 51 days at 18-22 degrees C and in 65 days at 16-17 degrees C. Released juveniles have a spherical shell with a thin rim of new shell material and a finely ciliated foot. Juvenile mean measurements are: length = 190 microm, width = 193 microm, and height = 210 microm.

Animals↗
PubMed2006

Cloned endangered species takin (Budorcas taxicolor) by inter-species nuclear transfer and comparison of the blastocyst development with yak (Bos grunniens) and bovine.

Interspecies cloning might be used as an effective method to conserve endangered species and to support the study of nuclear-cytoplasm interaction. In this study, we describe the development of takin-bovine embryos in vitro produced by fusing takin ear fibroblasts with enucleated bovine oocytes and examine the fate of mitochondrial DNA in these embryos. We also compare the blastocyst development of takin-bovine embryos with yak-bovine and bovine-bovine embryos and compare the cell numbers of the blastocyst. Our results indicate that: (1) takin-bovine cloned embryos can develop to the blastocyst stage in vitro (5%), (2) blastocyst mitochondria DNA are derived primarily from bovine oocytes in spite of a little takin donor cell mitochondrial DNA, (3) using the same cloned protocol, development efficiency is significantly different between bovine-bovine cloning, yak-bovine, and takin-bovine cloning (48 vs. 28% vs. 5%, P < 0.01), and (4) cell numbers in the blastocysts of the three species of embryos were not different. These results suggest that the bovine oocytes can reprogram the takin, yak, and bovine fibroblast nuclei. However, the development efficiency of intra-species cloning tends to be higher than inter-species cloning; the more close the species of the donor cell is to the recipient oocyte (yak versus takin), the greater the blastocyst development in vitro.

Amino Acid Sequence↗
PubMed2002

Impact of selenium and other trace elements on the endangered adult razorback sucker.

A study was conducted with endangered the razorback sucker (Xyrauchen texanus) to determine if environmental exposure to selenium in flooded bottomland sites affected survival, growth, and egg-hatching success. Adults were stocked at three sites adjacent to the Colorado River near Grand Junction, Colorado, in July 1996: hatchery ponds at Horsethief Canyon State Wildlife Area (referred to here as Horsethief; the reference site), a diked tertiary channel at Adobe Creek, and North Pond at Walter Walker State Wildlife Area (WWSWA). Fish were collected in April 1997 and spawned. After two spawnings adults from the three sites were held at Horsethief for an 86-day selenium depuration period. Selenium concentrations at Horsethief were 1.4-3.0 microg/L in water, 0.8-0.9 microg/g in sediment, 4.5 microg/g in muscle plug, and 6.0 microg/g in eggs; at Adobe Creek, <0.7-4.5 microg/L in water, 1.2-2.5 microg/g in sediment, 16-20 microg/g in zooplankton, 9.6 microg/g in muscle plug, and 40 microg/g in eggs; and at North Pond, 3.2-17 microg/L in water, 16-94 microg/g in sediment, 32-48 microg/g in zooplankton, 14 microg/g in muscle plug, and 55 microg/g in eggs. During the depuration period, when adults from Adobe Creek and North Pond were held at Horsethief, the fish lost 7%-13% of their selenium burden in 59 days and 14%-21% in 86 days. Larvae from North Pond adults had the most deformities, followed by Adobe Creek adults, with the fewest deformities found in the Horsethief adults.

Animals↗
PubMedDate not supplied

Morphological representation in an endangered, polysynthetic language.

This article presents the results from an initial psycholinguistic study of patterns of morphological representation in Dene Suliné (Chipewyan), an indigenous and highly endangered language spoken in Northwestern Canada. Our investigation focused on how morphological knowledge in this polysynthetic language is affected across various levels of language attrition by employing a morphological segmentation task and an off-line lexical decision task. We discuss the manner in which these tasks target different aspects of morphological ability and then turn to methodological issues associated with conducting psycholinguistic studies with language users that differ in levels of age, education, literacy, and bilingualism (Dene- English). Finally, we report on the challenges of doing psycholinguistic research outside the confines of a university setting and make some recommendations to other researchers who might wish to undertake similar studies.

Humans↗
PubMed1995

Hazard assessment of inorganics to three endangered fish in the Green River, Utah.

Acute toxicity tests were conducted with three life stages of Colorado squawfish (Ptychocheilus lucius), razorback sucker (Xyrauchen texanus), and bonytail (Gila elegans) in a reconstituted water quality simulating the middle part of the Green River of Utah. Tests were conducted with boron, lithium, selenate, selenite, uranium, vanadium, and zinc. The overall rank order of toxicity to all species and life stages combined from most to least toxic was vanadium = zinc > selenite > lithium = uranium > selenate > boron. There was no difference between the three species in their sensitivity to the seven inorganics based on a rank-order evaluation at the species level. Colorado squawfish were 2-5 times more sensitive to selenate and selenite at the swimup life stage than older stages, whereas razorback suckers displayed equal sensitivity among life stages. Bonytail exhibited equal sensitivity to selenite, but were five times more sensitive to selenate at the swimup life stage than the older stages. Comparison of 96-hr LC50 values with a limited number of environmental water concentrations in Ashley Creek, Utah, which receives irrigation drainwater, revealed moderate hazard ratios for boron, selenate, selenite, and zinc, low hazard ratios for uranium and vanadium, but unknown ratios for lithium. These inorganic contaminants in drainwaters may adversely affect endangered fish in the Green River.

Animals↗
PubMed1998

Temporal trends in metal levels in eggs of the endangered roseate tern (Sterna dougallii) in New York.

Female birds sequester certain organic and inorganic compounds in their eggs which have been widely used as a bioindicator for examining the body burdens of contaminants and therefore the temporal and spatial trends of the contaminants in the environment. The same analyses can also reflect the status or vulnerability of the indicator species. Extensive bridge de-leading activities in the New York Bight (Cape May to Montauk) in the early 1990s coincided with a long-term study of the endangered roseate tern (Sterna dougallii) on Long Island, New York, affording the opportunity to test the utility of such fish-eating species as bioindicators of lead contamination, as well as the potential impact on the bird population itself. In this paper we test the null hypothesis that there were no temporal trends between 1989 and 1994 in metal levels in eggs of roseate terns nesting at Cedar Beach, Long Island, where the birds have been declining since the late 1980s. We report levels and trends for cadmium, chromium, manganese, mercury, and selenium as well as lead in abandoned eggs collected each year. There were significant interyear differences for all metals, with 1990 to 1992 generally having higher levels than 1989 and 1994. The yearly differences were particularly prominent for lead, where the 10-fold increase may have been partially due to the increased removal of leaded paint from bridges in the early 1990s, leading to increased lead in the aquatic environment. Cadmium and chromium are also released during de-leading. The causes for the higher levels in the other metals in the early 1990s are unclear. Metal levels in roseate tern eggs are several times higher than the median reported for most birds, and the possible impact on the population requires study.

Animals↗
PubMed2001

The Coachella valley fringe-toed lizard (Uma inornata): genetic diversity and phylogenetic relationships of an endangered species.

A phylogeny was reconstructed for 23 populations of fringe-toed lizards (genus Uma) from the three most northern species of the genus, including the Mojave fringe-toed lizard U. scoparia, the Colorado Desert fringe-toed lizard U. notata, and the endangered Coachella Valley fringe-toed lizard U. inornata. The outgroup taxa were the zebra-tailed lizard, Callisaurus draconoides; the lesser earless lizard, Holbrookia maculata; and the greater earless lizard, Cophosaurus texanus. Evaluation of 1630 combined nucleotide sequence from the mitochondrial genes ATPase 6 and cytochrome b yielded 10 most parsimonious trees. Reweighting the characters using the rescaled consistency index eliminated eight of these trees. The remaining two trees differ only in the placement of two individuals from the Superstition Mountains which either formed a monophlyetic unit or grouped with one individual from the Anza-Borrego population. The preferred phylogeny, one more consistent with geography, had two primary clades: one consisting of U. scoparia and the other placing U. inornata inside the clade containing U. notata. Uma inornata was most closely related to nearby U. notata notata, as opposed to more distant U. notata rufopunctata.

Adenosine Triphosphatases↗
PubMed1993

Paternity testing of endangered species of birds by DNA fingerprinting with non-radioactive labelled oligonucleotide probes.

In the last years, DNA fingerprinting became the most powerful tool for identification and paternity testing in man. The success of this method encouraged the German Federal Ministry of Environment, Natural Protection and Reactor Safety to apply DNA fingerprinting in the field of protection of endangered species of birds, such as birds of prey or parrots. In the last three years, we received more than 400 blood and tissue samples of 23 species of birds of prey or parrots, most of them obtained by confiscation, to establish paternity and legal breeding success. We used digoxigenated oligonucleotide probes, mainly (GGAT)4 and (GACA)4 for hybridization. In most cases of confiscated families of birds, paternity testing showed exclusions of nestlings.

Animal Husbandry↗
PubMed1994

Genetic differentiation in a captive population of the endangered Siberian crane (Grus leucogeranus Pall.).

DNA fingerprinting, followed by multivariate analysis of data, was used to characterize genetic heterogeneity in captive populations of the endangered Siberian and sandhill cranes. The genetic structure revealed reflected the natural population and species distributions. The relevant groups differed not only from each other, but also from interspecies and inter-population hybrids bred in captivity. In this study we have tested an approach to the analysis of population structure based on individual genotypes. Interpretation of fingerprinting data by means of the analytical system applied here is a useful and reliable procedure for the estimation of genetic relationships between individuals.

Animals↗
PubMed1980

Biochemical markers in a species endangered by introgression: the red wolf.

The red wolf (Canis rufus), native to much of the southeastern United States, is endangered by man's activities and by hybridization with other species of the genus Canis. The absence of diagnostic morphological markers to distinguish the red wolf from its hybrids has led to the application of the methods of biochemical genetics to this problem. The finding of a unique electrophoretically determined allele with a distribution congruent with the geographical distribution of the remaining red wolf population is reported.

Acid Phosphatase↗
PubMed1996

On the Value of Endangered and Other Species

/ This paper describes two frameworks-utilitarian and Kantian-society uses to make decisions concerning environmental management and, in particular, species protection. The utilitarian framework emphasizes the consequences of choices for prior preferences. A perfectly competitive market, on this model, correctly values environmental resources. The Kantian approach identifies rules appropriate to recognized situations given the identity of the decision maker. It relies on democratic political processes and institutions to provide the means by which citizens determine the identity of their community-its moral character and aspirations-and match appropriate rules to recognized situations. This paper argues that markets do not fail in any general way in measuring the economic value of plants and animals. Market prices, in general, correctly represent the marginal or exchange value of species. If society legislates against extinction, this must be understood as an exercise in Kantian decision making in view of the moral value of species, not as an attempt to "correct" a market failure or to promote social welfare or utility.KEY WORDS: Biodiversity; Endangered species; Cost-benefit analysis; Social choice; Contingent valuation; Kant

Journal Article↗
PubMed1978

[The so-called recanalisation of cotyledonary vessels with endangitis obliterans of placenta vessels (author's transl)].

With a graphic reconstruction on serial sections, performed with placentas which altogether showed so-called recanalisation, it is possible to work out the fact, that the recanalisation is an effect of the paravascular capillary network and with it to clarify the problem of the so-called recanalisation. It is proved, that the paravascular capillaries undertake compensatory hemodynamic functions and this undertaking of function prevents a complete occlusion of the cotyledonary vessels, so that you have to speak of restlumen and restflow but not of recanalisation. The endangitis obliterans of cotyledonary vessels is again unequivocally pointed out by this phenomenon as a intravital process.

Capillaries↗
PubMed2006

Factors affecting in vitro plant regeneration of the critically endangered Mediterranean knapweed (Centaurea tchihatcheffii Fisch et. Mey).

Habitat destruction has resulted in the extinction of many plant species from the earth, and many more face extinction. Likely, the annual endemic Mediterranean knapweed (Centaurea tchihatcheffii) growing in the Golbasi district of Ankara, Turkey is facing extinction and needs urgent conservation. Plant tissue culture, a potentially useful technique for ex situ multiplication, was used for the restoration of this ill-fated plant through seed germination, micropropagation from stem nodes, and adventitious shoot regeneration from immature zygotic embryos. The seeds were highly dormant and very difficult to germinate. No results were obtained from the micropropagation of stem nodes. However, immature zygotic embryos showed the highest adventitious shoot regeneration on Murashige and Skoog (MS) medium, containing 1 mg l(-1) kinetin and 0.25 mg l(-1) NAA. Regenerated shoots were best rooted on MS medium containing 1 mg l(-1) IBA and transferred to the greenhouse for flowering and seed set. As such, the present work is the first record of in vitro propagation of critically endangered C. tchihatcheffii, using immature zygotic embryos, and is a step forward towards conservation of this indigenous species.

Centaurea↗
PubMed2006

[Treatment of vitally endangered anorexia nervosa patients based on guardianship laws].

Anorexia nervosa is a psychiatric disorder occurring primarily in young women. Especially when chronic or the body mass index is less than 12 kg/m(2), it has a mortality of up to 20%. Often these patients are admitted to emergency units and treated internistically. If they accept psychiatric treatment, they are normally transferred to specialized psychosomatic units for further therapy. If patients are not able to accept necessary further therapy to overcome the danger to health and life, the question arises in terms of guardianship law of whether they are able to handle their personal concerns alone. After several vitally endangered anorexia nervosa patients had been admitted to our closed psychiatric ward, we developed a therapeutic concept for this subgroup of patients, taking the possibilities of guardianship law into account. This concept aims at restoring the body weight continuously and finally enable the patients to be transferred to less restrictive psychosomatic units. The chosen treatment is shown with the therapy courses of 25 patients treated according to this concept.

Adolescent↗
PubMed2005

Assessing contaminant sensitivity of endangered and threatened aquatic species: part III. Effluent toxicity tests.

Toxicity tests using standard effluent test procedures described by the U.S. Environmental Protection Agency were conducted with Ceriodaphnia dubia, fathead minnows (Pimephales promelas), and seven threatened and endangered (listed) fish species from four families: (1) Acipenseridae: shortnose sturgeon (Acipenser brevirostrum); (2) Catostomidae; razorback sucker (Xyrauchen texanus); (3) Cyprinidae: bonytail chub (Gila elegans), Cape Fear shiner (Notropis mekistocholas) Colorado pikeminnow (Ptychocheilus lucius), and spotfin chub (Cyprinella monacha); and (4) Poecillidae: Gila topminnow (Poeciliopsis occidentalis). We conducted 7-day survival and growth studies with embryo-larval fathead minnows and analogous exposures using the listed species. Survival and reproduction were also determined with C. dubia. Tests were conducted with carbaryl, ammonia--or a simulated effluent complex mixture of carbaryl, copper, 4-nonylphenol, pentachlorophenol and permethrin at equitoxic proportions. In addition, Cape Fear shiners and spotfin chub were tested using diazinon, copper, and chlorine. Toxicity tests were also conducted with field-collected effluents from domestic or industrial facilities. Bonytail chub and razorback suckers were tested with effluents collected in Arizona whereas effluent samples collected from North Carolina were tested with Cape Fear shiner, spotfin chub, and shortnose sturgeon. The fathead minnow 7-day effluent test was often a reliable estimator of toxic effects to the listed fishes. However, in 21 % of the tests, a listed species was more sensitive than fathead minnows. More sensitive species results varied by test so that usually no species was always more or less sensitive than fathead minnows. Only the Gila topminnow was consistently less sensitive than the fathead minnow. Listed fish species were protected 96% of the time when results for both fathead minnows and C. dubia were considered, thus reinforcing the value of standard whole-effluent toxicity tests using those two species. If the responses of specific listed species are important for management decisions, our study supports the value in developing culture and testing procedures for those species.

Animals↗
PubMed1999

Metal concentrations in the eggs of endangered Florida scrub-jays from central Florida.

We analyzed metal levels in the eggs of the endangered Florida scrub-jay (Aphelocoma coerulescens), an extremely sedentary and modestly long-lived passerine bird. Eggs were obtained as part of the long-term study of this species at the Archbold Biological Station, located in south central Florida. Following a brief and usually short dispersal, Florida scrub-jays remain in a permanent territory in their scrub oak habitat, where they feed mainly on insects and acorns. As they are low on the food chain and sedentary, we expected levels of contaminants to be comparatively low and to reflect the local environment. No significant yearly differences existed for any metal between eggs collected in 1997 (n = 11) and 1998 (n = 5). Arithmetic mean metal concentrations (whole egg, dry weight) were low for arsenic (34 ppb), cadmium (25 ppb), mercury (74 ppb), and lead (66 ppb), intermediate for chromium (226 ppb), and higher for selenium (1,470 ppb) and manganese (2,230 ppb). Except for the low mercury value, all these means were within the range of mean values reported for a wide range of nonpasserine species, including those at high trophic levels, but are lower than concentrations associated with abnormalities in birds. The three essential elements (chromium, selenium, and manganese) were approximately normally distributed, whereas arsenic, cadmium, lead, and mercury were highly skewed (arithmetic mean much higher than geometric mean).

Animals↗