Decreasing genetic diversity in wild and captive populations of endangered Itasenpara bittering (Acheilognathus longipinnis) in the Himi region, central Japan, and recommendations for conservation

2014 ◽  
Vol 15 (4) ◽  
pp. 921-932 ◽  
Author(s):  
Yuji Yamazaki ◽  
Tomomi Nakamura ◽  
Miki Sasaki ◽  
Shizuka Nakano ◽  
Masaki Nishio
2015 ◽  
Vol 37 (2) ◽  
pp. 170 ◽  
Author(s):  
Emily J. Miller ◽  
Mark D. B. Eldridge ◽  
Keith Morris ◽  
Neil Thomas ◽  
Catherine A. Herbert

The endemic Australian greater bilby (Macrotis lagotis) is a vulnerable and iconic species. It has declined significantly due to habitat loss, as well as competition and predation from introduced species. Conservation measures include a National Recovery Plan that incorporates several captive breeding programs. Two of these programs were established within 12 months of one another (1997/98), with the same number and sex ratio of founding individuals, but executed different breeding strategies: (1) unmanipulated mating in semi–free range natural habitat versus (2) minimising mean kinship in large enclosures, with the supplementation of new individuals into both populations. This study evaluates the long-term genetic impact of these programs and examines the congruency between the pedigree studbook estimates of diversity and molecular data. Our data demonstrate that genetic diversity was maintained in both populations, with the supplementation of new individuals contributing to the gene pool. The studbook estimates of diversity and inbreeding are not consistent with the microsatellite data and should not solely be relied upon to evaluate the genetic health of captive populations. Our analyses suggest that captive breeding programs may not require costly and intensive management to effectively maintain long-term genetic diversity in a promiscuous species.


2021 ◽  
Author(s):  
Chao Du ◽  
Bai Mo ◽  
Wujiao Li ◽  
Wencong Liu ◽  
Zongxiu Hu ◽  
...  

Abstract Rhesus monkeyss (Macaca mulatta) are extensively used in the field of medical and psychological research as valuable experimental animals. 15 polymorphic chromosome-specific microsatellite markers were used to analyze the genetic diversity and population structure in two captive individuals. A total of 155 alleles were identified, with the number of alleles per locus ranging from 7 to 15, giving an average number of 10.3 alleles per locus. The mean number of effective alleles (Ne), observed heterozygosity (Ho), expected heterozygosity (He), and the polymorphism information content (PIC) were 5.602, 0.7297, 0.8016, and 0.7716, respectively. The populations HS and XJ shared partial common alleles, however, the remaining in XJ were not detected. Structure analysis indicated that two populations belong to three genetic lineages. AMOVA showed that the genetic variance was 91% among individuals, while it was 9% among populations, respectively. The bottleneck effect analysis revealed that the two captive populations were in accordance with mutation-drift equilibrium. In the comparison of the genetic parameters and structure between the HS and XJ, we speculated that the genetic diversity was higher, which may be attributed to the exchange of germplasm resources and the input of new individuals from wild populations.


Flora ◽  
2008 ◽  
Vol 203 (3) ◽  
pp. 187-196 ◽  
Author(s):  
Takafumi Ohsawa ◽  
Yoko Saito ◽  
Haruo Sawada ◽  
Yuji Ide

2000 ◽  
Vol 75 (3) ◽  
pp. 331-343 ◽  
Author(s):  
ARMANDO CABALLERO ◽  
MIGUEL A. TORO

Genetic parameters widely used to monitor genetic variation in conservation programmes, such as effective number of founders, founder genome equivalents and effective population size, are interrelated in terms of coancestries and variances of contributions from ancestors to descendants. A new parameter, the effective number of non-founders, is introduced to describe the relation between effective number of founders and founder genome equivalents. Practical recommendations for the maintenance of genetic variation in small captive populations are discussed. To maintain genetic diversity, minimum coancestry among individuals should be sought. This minimizes the variances of contributions from ancestors to descendants in all previous generations. The method of choice of parents and the system of mating should be independent of each other because a clear-cut recommendation cannot be given on the latter.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12212
Author(s):  
Deepanwita Purohit ◽  
Shivakumara Manu ◽  
Muthuvarmadam Subramanian Ram ◽  
Shradha Sharma ◽  
Harika Chinchilam Patnaik ◽  
...  

Long-term captive populations often accumulate genetic changes that are detrimental to their survival in the wild. Periodic genetic evaluation of captive populations is thus necessary to identify deleterious changes and minimize their impact through planned breeding. Pygmy hog (Porcula salvania) is an endangered species with a small population inhabiting the tall sub-Himalayan grasslands of Assam, India. A conservation breeding program of pygmy hog from six founders has produced a multi-generational captive population destined for reintroduction into the wild. However, the impact of conservation breeding on its genetic diversity remained undocumented. Here, we evaluate temporal genetic changes in 39 pygmy hogs from eight consecutive generations of a captive population using genome-wide SNPs, mitochondrial genomes, and MHC sequences, and explore the relationship between genetic diversity and reproductive success. We find that pygmy hog harbors a very low genome-wide heterozygosity (H) compared to other members of the Suidae family. However, within the captive population we find excess heterozygosity and a significant increase in H from the wild-caught founders to the individuals in subsequent generations due to the selective pairing strategy. The MHC and mitochondrial nucleotide diversities were lower in captive generations compared to the founders with a high prevalence of low-frequency MHC haplotypes and more unique mitochondrial genomes. Further, even though no signs of genetic inbreeding were observed from the estimates of individual inbreeding coefficient F and between individuals (FIS) in each generation, the kinship coefficient showed a slightly increasing trend in the recent generations, due to a relatively smaller non-random sample size compared to the entire captive population. Surprisingly, male pygmy hogs that had higher heterozygosity also showed lower breeding success. We briefly discuss the implications of our findings in the context of breeding management and recommend steps to minimize the genetic effects of long-term captive breeding.


2016 ◽  
Author(s):  
Marie Collet ◽  
Chloé Vayssade ◽  
Alexandra Auguste ◽  
Laurence Mouton ◽  
Emmanuel Desouhant ◽  
...  

AbstractSex determination is ruled by haplodiploidy in Hymenoptera, with haploid males arising from unfertilized eggs and diploid females from fertilized eggs. However, diploid males with null fitness are produced under Complementary Sex Determination (CSD), whenindividuals are homozygous for this locus. Diploid males are expected to be more frequent in genetically eroded populations (such as islands and captive populations), as genetic diversity at the csd locus should be low. However, only a few studies have focused on the relation between population size, genetic diversity and the proportion of diploid males in the field. Here, we developed new microsatellites markers in order to assess and compare genetic diversity and diploid male proportion in populations from three distinct habitat types (mainland, island or captive), in the parasitoid wasp Venturia canescens. Eroded genetic diversity and higher diploid male proportion were found in island and captive populations, and habitat type had large effect on genetic diversity. Therefore, diploid male proportion reflects the decreasing genetic diversity in small and isolated populations. Thus, Hymenopteran populations can be at high extinction risk due to habitat destruction or fragmentation.


2018 ◽  
Vol 5 (2) ◽  
pp. 171901 ◽  
Author(s):  
L. Allen ◽  
K. L. Sanders ◽  
V. A. Thomson

Parthenogenesis is a form of asexual reproduction by which embryos develop from unfertilized eggs. Parthenogenesis occurs in reptiles; however, it is not yet known to occur in the widespread elapid snakes (Elapidae), which include well-known taxa such as cobras, mambas, taipans and sea snakes. Here, we describe the production of viable parthenogens in two species of Australo-Papuan elapids with divergent reproductive modes: the oviparous coastal/Papuan taipan ( Oxyuranus scutellatus ) and the viviparous southern death adder ( Acanthophis antarcticus ). Analyses of nuclear SNP data excluded paternity for putative fathers and convincingly demonstrated asexual reproduction, thus representing the first evidence of facultative parthenogenesis in Elapidae. Our finding has broad implications for understanding the evolution of reproductive diversity in snakes, as well as managing the conservation of genetic diversity in wild and captive populations.


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