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PubMed2026

Accounting for recombination rate variation improves inference of barrier loci and reveals the role of both natural and sexual selection in an incipient bird radiation.

Examining genomic patterns of differentiation across lineage pairs at different stages of the speciation continuum, in combination with recombination maps, can help disentangle the effects of linked and divergent selection and identify lineage-specific targets of selection that may act as barrier loci during speciation. Here, we apply this framework to genomic data from African and Indian Ocean bird species of the genus Zosterops (Zosteropidae) to identify candidate barrier loci between ecologically, phenotypically, and genetically distinct Reunion gray white-eye (Zosterops borbonicus) parapatric geographic forms. Using analyses that account for recombination rate variation, we show that putative targets of divergent selection are primarily located on the Z chromosome, except in comparisons between geographic forms that differ in their ecologies. Functional annotation revealed that candidate barrier loci between forms with similar environmental niches are associated with genes involved in song formation and immune function, whereas those between forms with different environmental niches are associated with adaptation to altitude, morphology, and song behavior. Our results highlight the combined roles of natural and sexual selection in the evolution of reproductive barriers in this incipient species radiation.

Animals↗
PubMed1994

Saturated molecular map of the rice genome based on an interspecific backcross population.

A molecular map has been constructed for the rice genome comprised of 726 markers (mainly restriction fragment length polymorphisms; RFLPs). The mapping population was derived from a backcross between cultivated rice, Oryza sativa, and its wild African relative, Oryza longistaminata. The very high level of polymorphism between these species, combined with the use of polymerase chain reaction-amplified cDNA libraries, contributed to mapping efficiency. A subset of the probes used in this study was previously used to construct an RFLP map derived from an inter subspecific cross, providing a basis for comparison of the two maps and of the relative mapping efficiencies in the two crosses. In addition to the previously described PstI genomic rice library, three cDNA libraries from rice (Oryza), oat (Avena) and barley (Hordeum) were used in this mapping project. Levels of polymorphism detected by each and the frequency of identifying heterologous sequences for use in rice mapping are discussed. Though strong reproductive barriers isolate O. sativa from O. longistaminata, the percentage of markers showing distorted segregation in this backcross population was not significantly different than that observed in an intraspecific F2 population previously used for mapping. The map contains 1491 cM with an average interval size of 4.0 cM on the framework map, and 2.0 cM overall. A total of 238 markers from the previously described PstI genomic rice library, 250 markers from a cDNA library of rice (Oryza), 112 cDNA markers from oat (Avena), and 20 cDNA markers from a barley (Hordeum) library, two genomic clones from maize (Zea), 11 microsatellite markers, three telomere markers, eleven isozymes, 26 cloned genes, six RAPD, and 47 mutant phenotypes were used in this mapping project. Applications of a molecular map for plant improvement are discussed.

Avena↗
PubMedDate not supplied

Esterase variation at three loci in meat ants.

The meat ant (Iridomyrmex purpureus) occurs in a number of color forms, with uncertain taxonomic status. Gel electrophresis of meat ant extracts, followed by nonspecific esterase staining, reveals several zones of activity. Allelic variation at three loci is proposed to account for variation in some of these zones. Two of the loci (Es-1, Es-2) appear to have recessive null alleles, whose frequencies have been estimated by the method of maximum likelihood. Geographic variation in allele frequency is attributed to behavioral and geographic subdivision of the population. Apparent disturbances in segregation ratios and deviations from Hardy-Weinberg equilibrium can be accounted for if it is argued that some nests contain more than one queen. Differences in gene frequency between sympatric populations of the red and blue forms of I. purpureus are observed, confirming their reproductive is isolation and sibling species status.

Alleles↗
PubMed1992

Sexual maturation in female gray short-tailed opossums, Monodelphis domestica, is dependent upon male stimuli.

The development of physiological responsiveness to male stimuli in peripubertal female gray short-tailed opossums was examined in this study. Prepubertal females were exposed directly or indirectly to male chemicals (odors) or to no male stimuli. All females exposed directly to deposited male stimuli (22/22) showed estrus at a mean (+/- SEM) age of 127 +/- 2 days. Only 59% (13/22) of females exposed indirectly showed estrus, and at an older mean age of 162 +/- 5 days (p less than 0.01). Vaginal estrus was not observed in any of the females isolated from male stimuli (0/11). Direct exposure of prepubertal females to male odors was associated with higher uterine weights compared to those of indirectly exposed and isolated females. Reproductive success, measured as litter production, of peripubertal females greater than 140 days old was comparable to adult reproductive success. This study has shown that reproductive maturation in pubertal female opossums requires male stimuli, that this stimulus appears to be pheromonal, and that direct exposure to deposited male odors is the most effective stimulus for female reproductive maturation.

Animals↗
PubMed2000

The genetics of obesity. Lessons for polycystic ovary syndrome.

Both polycystic ovary syndrome (PCOS) and obesity are common disorders with a complex phenotype. Both are presumably heterogeneous in etiology. Understanding the genetics of obesity, which has a longer and richer history, may therefore illuminate the genetics of PCOS, where major projects are now underway. Obesity may be the penultimate condition in which the effects of heredity and environment will forever mingle. Most obesity mutations identified to date (with the exception of the Agouti mutation) are inherited in an autosomal recessive manner. Therefore, it is unlikely that such mutations, even when identified in a human population, could explain only a fraction of the cases that make up the high prevalence of both of these disorders. Although the mouse models of single gene defects causing obesity contain many similar aspects of the PCOS phenotype such as obesity and subfecundity, there is no mouse model that mimics all aspects of the syndrome, especially the circulating androgen excess. This elevation in circulating androgens may be the sine qua non of the syndrome as indicated by our findings in sisters of PCOS probands that hyperandrogenemia may be the distintinctive reproductive phenotype. Isolation of PCOS and obesity genes may allow the development of targeted interventions that will lead to effective and safe treatment of both obesity and PCOS.

Adipocytes↗
PubMed2005

Identification of medically important molds by an oligonucleotide array.

Infections caused by fungi have increased in recent years. Accurate and rapid identification of fungal pathogens is important for appropriate treatment with antifungal agents. On the basis of the internal transcribed spacer 1 (ITS 1) and ITS 2 sequences of the rRNA genes, an oligonucleotide array was developed to identify 64 species (32 genera) of clinically important filamentous (or dimorphic) fungi. These 64 species included fungi causing superficial, cutaneous, subcutaneous, and invasive infections. The method consisted of PCR amplification of the ITS regions using a pair of universal primers, followed by hybridization of the digoxigenin-labeled PCR products to a panel of species- or group-specific oligonucleotides immobilized on a nylon membrane. Of 397 fungal strains (290 target and 107 nontarget strains) tested, the sensitivity and specificity of the array was 98.3% (285/290) and 98.1% (105/107), respectively. Misidentified strains were usually those belonging to the same genus of the target species or having partial homology with oligonucleotide probes on the membrane. The whole procedure can be finished within 24 h starting from isolated colonies; reproductive structures, which are essential for the conventional identification methods, are not needed. In conclusion, the present array is a powerful tool for identification of clinically important filamentous fungi and may have the potential to be continually extended by adding further oligonucleotides to the array without significantly increasing the cost or complexity.

Fungi↗
PubMed1977

Serological typing of Pseudomonas aeruginosa: use of commercial antisera and live antigens.

A practical slide agglutination test, with commercial antisera (Difco) and live antigens (antigens of live bacteria) taken directly from 24-h antimicrobial susceptibility plates, has been established for serotyping Pseudomonas aeruginosa. Until recently, the lack of both a standard antigenic scheme and a source of commercial antisera has made serological typing of this organism impractical. A simplified procedure with 17 unabsorbed antisera and live antigens prepared from materials readily available in most clinical microbiology laboratories makes epidemiological typing of this organism possible in hospital laboratories. The distribution of each serotype examined in this study was determined by using 425 consecutive patient isolates from six different hospitals. The distribution of O antigen groups (live antigen) was as follows: O1, 11.5%; O2, 1.6%; O3, 3.8%; O4, 7.8%; O5, 4.2% O6, 27.1%; O7,8, 5.9%; O9, 6.8%; O10, 2.4%; O11, 8.2%; O12 through O17, each less than 1%. Ten and six-tenths percent of the above agglutinated in two antisera, 3.3% agglutinated in more than two antisera, and 5.2% did not agglutinate in any antisera. A comparison of live and heated antigens shows that 93.2% were typable with the live antigen, and 94.5% were typable with the heated antigen. When both antigens were used, we typed 96.3% of 725 isolates. The reproductibility and specificity of the serological procedure were examined. We recommend using the live antigen for routine serological typing in clinical microbiology laboratories for "in house" epidemiology and reserving the heated antigen for reference and research typing (and for those few cases where results cannot be obtained using the live antigen). The application of serotyping in the study of outbreaks of P. aeruginosa is also presented.

Agglutination Tests↗
PubMed1993

Population genetics and structure of Buryats from the Lake Baikal Region of Siberia.

Genetic polymorphisms of blood groups, serum proteins, red cell enzymes, PTC tasting, and cerumen types are reported for five Mongoloid populations of Buryats from the Lake Baikal region of Siberia (Russia). These groups are characterized by relatively high frequencies of alleles ABO*B, RH*D, cerumen D, GC*1F, ACP1*B, ESD*2, and PGD*C. Significant genetic heterogeneity between populations was demonstrated for the loci RH, MN, cerumen, PGD, ABO, GC, GLO, TF, and PGM1. Genetic distance analyses using five loci revealed a lower level of genetic microdifferentiation within the Buryat populations compared with other native Siberian groups. The distribution of gene markers in Buryats is similar to that found in neighboring Central Asian groups, such as the Yakuts and the Mongols. Intrapopulational analyses of the five Buryat subdivisions, based on R matrix and rii, indicate that one of the subdivisions is reproductively more isolated than the others and that two of the communities have received considerable gene flow. A nonlinear relationship was demonstrated between geographic and genetic distances of Buryat population subdivisions.

Adolescent↗
PubMedDate not supplied

Genotype analyses of Campylobacter isolated from the gastrointestinal tracts and the reproductive tracts of broiler breeder roosters.

Campylobacter is considered to be the leading bacterial etiologic agent of acute gastroenteritis in humans. Evidence implicates poultry as a major source of the organism for human illness; however, the pathways involved in Campylobacter contamination of poultry flocks, horizontal transmission and/or vertical transmission, remain unclear. Recent evidence implicates breeders as a potential source for Campylobacter contamination of the subsequent broiler offspring. In this investigation, Campylobacter isolated from feces, cloacal swabs, ceca, semen, and vas deferens of 12 breeder broiler roosters were genotyped by both flagellin A short variable region (flaA SVR) DNA sequence analysis and repetitive element (rep)-polymerase chain reaction (PCR). In 9 of 12 roosters, Campylobacter was isolated from multiple sites sampled. Comparison of multiple isolates obtained from individual roosters revealed variable results. In five of the nine roosters, all Campylobacter isolated demonstrated closely related flaA SVR DNA sequences as well as rep-PCR patterns; isolates from these roosters were collected from both the gastrointestinal and the reproductive tracts or from the gastrointestinal tract alone. The remaining four roosters had Campylobacter that were distinct by both typing methods. Isolates from two of these four roosters originated from both the gastrointestinal and the reproductive tracts. Isolates from the remaining two roosters originated from only the reproductive tract. Comparisons of all Campylobacter isolates recovered from a distinct sample type within either the reproductive tract or the gastrointestinal tract (feces, semen, cloaca, vas deferens, or ceca) were quite diverse. No relationship between the genotypes and the sample type could be ascertained. Further investigation is needed to determine the route of contamination and if the presence of Campylobacter within the rooster leads to contamination of the broiler offspring via the fertilized egg.

Animals↗
PubMed2004

Genetics and geographical variation of porcine reproductive and respiratory syndrome virus (PRRSV) in Thailand.

The Thai isolates of porcine reproductive and respiratory syndrome virus (PRRSV) were obtained from the Chulalongkorn University-Veterinary Diagnostic Laboratory (CU-VDL). Virus isolation was confirmed by immunoperoxidase monolayer assay (IPMA) using SDOW-17. The virus genotype was determined using nested multiplex RT-PCR (nm RT-PCR) of ORF 1b. The nm RT-PCR was able to detect at least 10TCID50/ml of PRRSV. Of 137 Thai isolates, 66.42% belonged to the European (EU) genotype and 33.58% to the North American (US) genotype. ORF5 products of the eight US strains (00CS1, 01NP1, 01UD6, 02CB13, 02KK1, 02PB1, 02SP2 and 02SP3) and the six EU strains (01CB1, 01RB1, 02BR1, 02CB12, 02SB2 and 03RB1) were sequenced for genetic variation analysis. The US strains of the Thai isolates are clustered within the same group and are more closely related to the IAF-EXP91 from Canada (89-90% nucleotide identity), whereas the EU strains were very similar to the EU prototype, Lelystad virus (87-97.5% nucleotide identity). The ORF5 nucleotide identities within the US genotype tested in this study compared to the US prototype, VR-2332 varied from 83.7 to 85.2%, whereas 83.5-85.5% amino acid identities were found. Based on the phylogenetic tree, each pair of the Thai isolates (01NP1 and 02KK1, 00CS1 and 01UD6, and 01CB1 and 01RB1) was identical despite they were collected from different provinces. Therefore, there was no geographic influence on the spreading of PRRSV in Thailand. Interestingly, 02CB12 (EU genotype) shared over 99% similarity of the ORF5 nucleotide sequence and 98.6% of amino acid identity with the European vaccine, Porcillis (AF378819). However, modified live virus vaccines for PRRSV have not yet been used in the swine population in Thailand. The results suggested that both US and EU genotypes exist in Thailand, genetic variation does occur in both genotypes, and the sources of the viruses appear to be from Canada and Northern Europe, respectively. In addition, the spreading of PRRSV in Thailand might be due to introducing infected replacement pigs or infected semen into the farm.

Amino Acid Sequence↗
PubMed1992

Isolated polyarteritis nodosa of the male reproductive system.

Polyarteritis nodosa (PAN) frequently affects the testis and epididymis. We describe a 29-year-old man with isolated PAN of the testis and review reported cases of isolated PAN of the testis or epididymis. Our patient underwent orchiectomy and at followup 17 months later was without evidence of recurrence or development of systemic PAN.

Adult↗
PubMed2006

Persistence, serodiagnosis and effects on semen characteristics of artificial Brucella ovis infection in red deer stags.

AIMS: To investigate the persistence of infection and serum antibody titres after infection of red deer (Cervus elaphus) stags with Brucella ovis, and compare these with those of rams. To assess the effects of recent and chronic infection on semen characteristics of stags. METHODS: Fourteen stags and eight rams were artificially infected with B. ovis by intravenous inoculation. Semen and blood samples were collected at approximately monthly intervals for 649 days. Semen samples were subjected to bacterial culture, and sera were tested for B. ovis antibodies using a complement fixation test (CFT) and an enzyme-linked immunosorbent assay (ELISA). At the end of the study, animals were slaughtered and reproductive organs subjected to bacterial culture. During the first and second breeding seasons, three and five semen samples, respectively, were evaluated from each stag for sperm motility and morphology. RESULTS: Twelve of 14 (86%) stags and 6/8 (75%) rams developed a patent B. ovis infection and shed the organism in semen. All six infected rams continued to shed B. ovis in semen throughout the 649-day study period, and at slaughter B. ovis was isolated from the reproductive tract and urinary bladder. In contrast, 10/12 (83%) infected stags stopped shedding B. ovis in semen 103-342 days after inoculation, and the organism could not be isolated from their reproductive tracts at slaughter. The remaining two infected stags shed B. ovis in semen throughout the study period and the organism was isolated from their reproductive tracts at slaughter. All inoculated animals initially developed serum antibody titres detectable using the B. ovis CFT and ELISA. For infected stags, the diagnostic sensitivity of these tests was 100% for the first 166 days, but decreased to 50-90% after this. The diagnostic sensitivity for the infected rams was 100% throughout the study period. Infection in stags resulted in variable effects on semen characteristics. Eight of 12 (67%) infected stags had a mean sperm motility of < 50%, and < 60% mean normal sperm in the first year of infection. Seven of these stags had resolved the infection by the following breeding season, and there was a significant improvement in sperm motility and morphology. CONCLUSIONS: Stags are as susceptible as rams to experimental B. ovis infection. However, the majority of infected stags resolved the infection within a year, whereas rams remained infected for at least 649 days (22 months). Serology, using CFT and ELISA, was effective at detecting infection during the first 166 days in both species, but after this time was less effective at detecting infection in stags than in rams. Infection with B. ovis had variable but generally deleterious effects on the semen characteristics of stags, which resolved following resolution of the infection. Differences in the characteristics of the disease in stags compared with rams mean that different control methods are warranted for the two species. CLINICAL RELEVANCE: Most stags infected with B. ovis are likely to resolve the infection within a year, and semen characteristics return to levels acceptable for breeding. Serology is useful for detection of infection in the early stages of the disease, but once disease has been present in the herd for some time false-negative reactions are likely to occur in individual stags.

Animals↗
PubMed2004

Porcine reproductive and respiratory syndrome virus field isolates differ in in vitro interferon phenotypes.

Type I interferons (IFN-alpha and -beta) play an important role in the innate host defense against viral infection by inducing antiviral responses. In addition to direct antiviral activities, type I IFN serves as an important link between the innate and adaptive immune response through multiple mechanisms. Therefore, the outcome of a viral infection can be affected by IFN induction and the IFN sensitivity of a virus. North American porcine reproductive and respiratory syndrome virus (PRRSV) field isolates were studied with regard to IFN-alpha sensitivity and induction in order to understand the role of type I IFN in PRRSV pathogenesis. PRRSV isolates were differentially sensitive to porcine recombinant IFN-alpha (rIFN-alpha) and varied in their ability to induce IFN-alpha in porcine alveolar macrophages (PAM) cultures as measured by a porcine IFN-alpha specific ELISA on cell culture supernatants. Fifty-two plaques were purified from three PRRSV isolates (numbers 3, 7, and 12) and tested for IFN sensitivity and IFN induction. Plaque-derived populations were composed of heterogeneous populations in terms of IFN-inducing capacity and sensitivity to rIFN-alpha. When macrophages infected with isolates 3, 7, or 12 were treated with polycytidylic acid (polyI:C), IFN-alpha production was enhanced. Cells infected with isolate 3 and treated with polyI:C showed the most consistent and strongest enhancement of IFN-alpha production. It was demonstrated that the relatively low concentrations of IFN-alpha produced by isolate 3 contributed to the enhanced IFN-alpha synthesis in response to polyI:C. Isolates 7 and 12 significantly suppressed the enhanced IFN-alpha production by isolate 3 in polyI:C treated cells. To determine if suppression was at the level of IFN-alpha transcription, quantitative RT-PCR was performed for IFN-alpha mRNA and compared to GAPDH and cyclophilin mRNA quantification. However, the relative number of IFN-alpha transcript copies did not correlate with IFN-alpha protein levels, suggesting a post-transcriptional mechanism of suppression. In summary, these results demonstrate that PRRSV field isolates differ both in IFN-alpha sensitivity and induction. Furthermore, a PRRSV field isolate strongly enhance polyI:C-induced IFN-alpha production in PAM cultures and this priming effect was suppressed by other PRRSV isolates.

Animals↗
PubMed1991

In vitro analysis of the murine heat shock response: implications for reproductive toxicology.

Lymphocytes isolated from two inbred mouse strains that differed in their genetically determined sensitivity to heat-induced exencephaly were used to compare the in vitro kinetics of heat shock protein synthesis in the two strains following hyperthermic exposure. Differences in protein synthesis were determined by densitometric analysis of autoradiograms of SDS-PAGE gels. The findings were consistent with those observed in vivo in that there was an immediate and prolonged synthesis of heat-shock proteins by lymphocytes from the heat sensitive SWV/SD strain, compared to the response observed in lymphocytes from the heat-resistant DBA/2J strain. These results indicate that an in vitro lymphocyte assay of the heat-shock response may be a useful tool for screening suspected teratogenic agents.

Animals↗
PubMed2000

Identification of a novel platelet-derived growth factor-like gene, fallotein, in the human reproductive tract.

We isolated the cDNA of a novel platelet-derived growth factor-like gene from human endometrium. The gene was named fallotein; it was 3007 bases in length, and encoded a protein of 345 amino acids. Antiserum against the fallotein protein can recognize a specific protein in the fallopian tube, with a molecular size in accordance with the anticipated size of fallotein. Fallotein mRNA is expressed in two molecular sizes, 3.8 and 2.9 kb, with the former being more abundant. High expression of the gene was found in the prostate, testis, and uterus. A weaker expression signal was found in the spleen, thymus, and small intestine, but expression of fallotein in the colon and peripheral blood leukocytes was negligible.

Amino Acid Sequence↗