Rates of inbreeding and genetic diversity in Iranian Holstein Cattle     

Mohsen Dadar  Saeid Ansari Mahyari  Mohammad Rokouei  Mohammd Ali Edriss 《Animal Science Journal》2014,85(10):888-894

The accumulation of inbreeding and the loss of genetic diversity is a potential problem in Holstein dairy cattle. The goal of this study was to estimate inbreeding levels and other measures of genetic diversity, using pedigree information from Iranian Holstein cattle. Edited pedigree included 1 048 572 animals. The average number of discrete generation equivalents and pedigree completeness index reached 13.4 and 90%, respectively. The rate of inbreeding was 0.3% per year. Effective number of founders, founder genomes, non‐founders and ancestors of animals born between 2003 and 2011 were 503, 15.6, 16.1 and 25.7, respectively. It was proven that the unequal founder contributions as well as bottlenecks and genetic drift were important reasons for the loss of genetic diversity in the population. The top 10 ancestors with the highest marginal genetic contributions to animals born between 2003 and 2011 and with the highest contributions to inbreeding were 48.20% and 63.94%, respectively. Analyses revealed that the most important cause of genetic diversity loss was genetic drift accumulated over non‐founder generations, which occurred due to small effective population size. Therefore, it seems that managing selection and mating decisions are controlling future co‐ancestry and inbreeding, which would lead to better handling of the effective population size.  相似文献   

Sensitive detection of the c‐KIT c.1430G>T mutation by mutant‐specific polymerase chain reaction in feline mast cell tumours     

M. Takanosu  M. Sato  Y. Kagawa 《Veterinary and comparative oncology》2014,12(2):138-142

Here, we describe the establishment of mutant‐specific polymerase chain reaction (PCR) for detection of a c‐KIT c.1430G>T mutation in feline mast cell tumours. Several mutations in feline c‐KIT have been identified, with the c.1430G>T mutation accounting for a significant portion of feline mast cell tumour mutations. The c.1430G>T mutation in c‐KIT exon 9 was detected in 15.7% (11 of 70) of samples by mutant‐specific PCR but in only 7.1% (5 of 70) by PCR–restriction fragment length polymorphism (RFLP) in the genomic DNA isolated from 70 formalin‐fixed paraffin‐embedded sections or cells collected by fine needle aspiration. Mutant‐specific PCR showed remarkably higher detection rate than did PCR–RFLP. DNA sequence analysis did not always yield identical results to those of mutant‐specific PCR, suggesting heterogeneity of tumour cells. Mutant‐specific PCR is a valid and efficient screening tool for detection of the c‐KIT c.1430G>T point mutation in feline mast cell tumours compared with PCR–RFLP and sequencing analysis.  相似文献   

Dominance in domestic dogs revisited: Useful habit and useful construct?     

《Journal of Veterinary Behavior: Clinical Applications and Research》2014,9(4):184-191

In the last decade, the validity and relevance of the dominance model was regularly put into question regarding relationships between canids like dogs and wolves, and consequently, human–dog relationships as well. The concept underlying this model, scientifically defined as an intervening variable reflecting status difference between individuals, is applicable when formal status signals symbolize the long-term relationship between individuals, resulting in a formalized dominance hierarchy. This article reviews the basics underlying the concept of dominance and reflects on the value and importance of some new quantitative studies on the applicability of the concept of dominance in domestic dogs. The conclusions are, first, that formal dominance is present in the domestic dog, expressed by context-independent unidirectional formal status signals. Consequently, formal dominance (e.g., submission) plays an important role in assessing status in dog–dog relationships. Second, that nonverbal status–related communication in humans resembles that in dogs to a considerable degree, and hence dogs may be well able to interpret this human status–related nonverbal communication from their perspective. Dominance is therefore also likely to play a role in human–dog relationships. Hence, the dominance concept might be useful to explain the development of certain problems in dog–dog and dog–human relationships. However, enforcing a dominant status by a human may entail considerable risks and should therefore be avoided.  相似文献   

2株猪繁殖与呼吸综合征病毒的分离、鉴定及遗传进化分析     

孙龙  刘宇  黄震 《中国畜牧兽医》2014,41(3):33-38

Two strains of porcine reproductive and respiratory syndrome viruses (PRRSV) were isolated from serum of some pig farms in Guangdong province and showed PRRSV positive in RT-PCR testing. The two viruses could passage stably and cause typical cenotaphic effect, they were named as LZ-GD and LB-GD. The analysis of variable region sequences of ORF5 and Nsp2 of the two viruses showed that LZ-GD and LB-GD strains were far to Europe strain Lelystad, the homology of nuclear nucleotide sequence were 63.5% and 63.8%, respectively, with classic American strain VR-2332 were 88.7% and 89.1%, respectively, and that with highly pathogenic JXA-1 strain were 99.2% and 99.3%, respectively. There were 30 amino acids deletion in Nsp2. It shared the deletion with JXA-1, HUN4 and other pathogenic variant. Thus, the two strains of PRRSV belonged to highly pathogenic American type.  相似文献   

Parentage assignment of stocked black sea bream <Emphasis Type="Italic">Acanthopagrus schlegelii</Emphasis> in Hiroshima Bay using microsatellite DNA markers   总被引：1，自引：0，他引：1  

Dal-Sang Jeong  Enrique Blanco Gonzalez  Kagayaki Morishima  Katsutoshi Arai  Tetsuya Umino 《Fisheries Science》2007,73(4):823-830

The genetic contribution of 51 broodstock, comprising 29 females and 22 males, reared at Hiroshima City Marine Products Promotion Center for the production of stocked black sea bream was monitored during two consecutive years using seven microsatellite DNA loci. The high discrimination ability of these markers was reflected in the polymorphic identification content (PIC=0.831), the exclusion probability (Q≈1), and the low probability of identity index (I=3.635⁻¹⁰). The total number of breeders contributing to the mating process was estimated at 32 (62.7%) in 2000 and 30 (58.8%) in 2001. On pedigree reconstruction, 69.3% of the offspring were successfully assigned to a single broodstock pair. Loss of alleles accounted for 16.9% during seed production; nevertheless, 90.9% of males and 69.0% of females participated in the mating process. Based on microsatellite genetic tagging, 58.9% of the fish sampled during the two months after release were identified as hatchery stock, presenting no significant differences from wild conspecifics in either fork length or body weight.  相似文献   

Genetic divergence of kingfish from Japan, Australia and New Zealand inferred by microsatellite DNA and mitochondrial DNA control region markers   总被引：3，自引：0，他引：3  

Estu Nugroho  Douglas J Ferrell  Peter Smith  Nobuhiko Taniguchi 《Fisheries Science》2001,67(5):843-850

ABSTRACT: Genetic polymorphism in kingfish, collected from coastal waters of Japan, Australia and New Zealand, were examined using microsatellite (MS) DNA and mitochondrial DNA (mtDNA) control region markers. Sixteen to 25.7 alleles per locus were observed in three MS markers, while the average observed (and expected) heterozygosities were 0.782 (0.918), 0.750 (0.809) and 0.650 (0.888) for Australian, Japanese and New Zealand kingfish, respectively. Twelve mtDNA haplotypes were detected by the digestion of control region sequences with five endonucleases: Hae III, Hinf I Mbo I, Rsa I and Taq I. Significant genetic divergence was observed between the kingfish population from Japan and those from Australia–New Zealand. There was no significant differentiation among the Australian and New Zealand population samples.  相似文献   

Microsatellite variability in natural populations of the blackspot seabream Pagellus bogaraveo (Brünnick, 1768): a database to access parentage assignment in aquaculture     

Andreia Lemos  Ana Isabel Freitas  Ana Teresa Fernandes  Rita Gonçalves  José Jesus  Carlos Andrade  & António Brehm 《Aquaculture Research》2006,37(10):1028-1033

Eight microsatellite loci previously reported were assessed for their utility in parentage assignment in 96 individuals belonging to natural populations of the blackspot seabream Pagellus bogaraveo (Brünnick, 1768) from the Mediterranean and Northeast Atlantic regions. At the mtDNA level, no differentiation was found between these two regions but based on microsatellite data an overall discrete genetic differentiation is perceivable between the two regions separated by the Strait of Gibraltar. The number of alleles per locus ranged from 8 to 30. A database constructed with allele frequency data from six populations was used in a simulation parentage assignment test using the software cervus . The test showed that the number of markers used is enough to perform parentage assignments with real data. The polymorphic information content for each locus was very high (mean value of 0.849), with a total exclusionary power of 0.9995. In summary, seven of the eight microsatellites analysed proved to be sufficient and powerful tools for parentage assignment in hatcheries and the allele frequency data given here can be used to perform pedigree analysis against which real data may be tested.  相似文献   

Genetic covariation in production traits of sub-adult black bream Acanthopagrus butcheri after grow-out     

Robert G Doupé  & Alan J Lymbery 《Aquaculture Research》2005,36(11):1128-1132

Predicting the suitability and reliability of traits associated with juvenile growth as indirect selection criteria for choosing future broodstock requires accurate and repeatable estimates of genetic (co)variation for growth traits at different ages. We compared juvenile wet weight of black bream Acanthopagrus butcheri (Munro) at 6 months of age with wet weight, dressed weight, fillet yield and gonad weight in tagged individuals at 18 months of age, following 12 months of farm grow‐out. Fish survival and tag retention was high, and there was significant among‐family variation for all traits. The phenotypic correlations among wet weight, dressed weight and fillet yield at 18 months of age were very high (0.93–0.97) and similar to their genetic correlations (0.96). Importantly, the phenotypic correlations between wet weight at 6 months and wet weight, dressed weight and fillet yield at 18 months were high (0.63–0.65), and so too were their genetic correlations (0.66–0.73), indicating the potential for using wet weight in the hatchery as a selection criterion for improved weight and meat yield of fish at harvest. Gonad weight shared little or no phenotypic or genetic correlation with these other traits, suggesting that selection for faster growing fish will not affect fecundity or sexual maturation rate. It appears, however, that cultured black bream do become sexually mature more rapidly than wild fish, as 78% of all fish harvested in this study had developing or mature gonads, whereas less than 50% of fish in wild populations are reproductively mature by the same age. Precocious sexual development may lead to uncontrolled spawning in grow‐out ponds and a potential loss of selection gains.  相似文献   

文蛤北方种群生化遗传结构与变异的研究   总被引：1，自引：0，他引：1  

刘馨  孙祥山  高悦勉 《水产科学》2006,25(4):179-183

采用聚丙烯酰胺凝胶电泳技术,对文蛤5个北方种群进行了生化遗传分析。结果表明:文蛤5个天然种群的多态座位比例为0.475±0.064;平均杂合度为0.212±0.026,总体上遗传多样性较好,遗传变异水平较高。在各多态座位中有78.95%的座位符合Hardy-W e inberg平衡,有65.79%的座位d值为正,34.21%的座位为近交座位,存在近交,但近交程度不高。通过聚类分析可以初步判定,这5个群体同属于一个种,种群间由于地理隔离已形成了不同的地理种群。  相似文献   

Quantitative genetic parameter estimates for size and growth rate traits in Pacific white shrimp, Penaeus vannamei (Boone 1931) when reared indoors   总被引：4，自引：0，他引：4  

Carlos I Pérez-Rostro  & Ana M Ibarra 《Aquaculture Research》2003,34(7):543-553

Heritabilities of size traits and growth rate traits, as well as genetic, phenotypic and environmental correlations were estimated at three ages for a captive population of Pacific white shrimp (Penaeus vannamei) grown indoors. A covariate, mean size or mean growth rate during early growth in individual tanks before tagging and mixing, was introduced in the analyses to reduce the error caused by unique previous growth conditions on variance components. Heritabilities of size traits increased with age, with the h² for TL, AL, TWt and Wi1AS being 0.15, 0.20, 0.20 and 0.22, respectively, at 17 weeks, increasing to 0.28, 0.33, 0.34 and 0.35 at 29 weeks of age. Heritabilities of growth rate traits estimated between consecutive growth periods decreased from the first (h² for ΔTL 0.65, ΔAL 0.71, ΔTWt 0.63 and ΔWi1AS 0.84) to the second period (h² for ΔTL 0.34, ΔAL 0.50, ΔTWt 0.54 and ΔWi1AS 0.52). Phenotypic correlations were always larger than genetic correlations for both, size and growth rate traits. Genetic correlations between size traits within age were high (r_G >0.95), but those between the same size trait at different ages decreased as the age difference increased in spite of a consistently high environmental correlation (r_E 0.80–0.85) between the same trait at different ages. Phenotypic and genetic correlation's between the same growth rate trait at the two different growth periods evaluated were negative or zero (r_G TL –0.26, AL –0.24, Wi1AS 0.00) with the exception of total weight (r_G TW 0.35) and the environmental correlations between growth periods were also low (r_E 0.13–0.32).  相似文献