Tests for sex‐biased dispersal using bi‐parentally inherited genetic markers

This study investigates the genetic effect of an indigenous tradition of deliberate and controlled interbreeding between wild and domestic Rangifer. The results are interpreted in the context of conservation concerns and debates on the origin of domestic animals. The study is located in Northeastern Zabaĭkal'e, Russia at approximately 57 degrees North latitude. Blood and skin samples, collected from wild and domestic Rangifer, are analyzed for their mtDNA and microsatellite signatures. Local husbandry traditions are documented ethnographically. The genetic data are analyzed with special reference to indigenous understandings of the distinctions between local domestic types and wild Rangifer. The genetic results demonstrate a strong differentiation between wild and domestic populations. Notably low levels of mtDNA haplotype sharing between wild and domestic reindeer, suggest mainly male‐mediated gene flow between the two gene pools. The nuclear microsatellite results also point to distinct differences between regional domestic clusters. Our results indicate that the Evenki herders have an effective breeding technique which, while mixing pedigrees in the short term, guards against wholesale introgression between wild and domestic populations over the long term. They support a model of domestication where wild males and domestic females are selectively interbred, without hybridizing the two populations. Our conclusions inform a debate on the origins of domestication by documenting a situation where both wild and domestic types are in constant interaction. The study further informs a debate in conservation biology by demonstrating that certain types of controlled introgression between wild and domestic types need not reduce genetic diversity.

Section: Discussionsupporting

confidence: 81%

Maintaining genetic integrity of coexisting wild and domestic populations: Genetic differentiation between wild and domestic Rangifer with long traditions of intentional interbreeding

Anderson

Kvie

Davydov

et al. 2017

“…Although this result should be regarded with caution since the ability of the tests performed to detect the bias in dispersal is limited mainly due to the lack of extreme bias in dispersal, the low to moderate dispersal estimates, and the number of loci and samples analyzed (Goudet et al., 2002), previous franciscana dolphin studies also found a lack of sex‐biased dispersal (Costa Urrutia et al., 2012; Méndez et al., 2008), supporting our findings.…”

Section: Discussionmentioning

confidence: 80%

“…The second test compared relatedness (r) between males and females; within populations, r should be greater in the philopatric sex than in the dispersing one. The third test compared F IS statistics between sexes; a sex‐biased dispersal should be reflected in a statistically significant higher F IS for the dispersal sex (Goudet, Perrin, & Waser, 2002). The other tests consisted in calculating the mean and variance of assignment indices ( mAIC and vAIC , respectively) to determinate the probability of a genotype originating from the population in which the individual was collected (Favre, Balloux, Goudet, & Perrin, 1997).…”

Section: Methodsmentioning

confidence: 99%

“…The other tests consisted in calculating the mean and variance of assignment indices ( mAIC and vAIC , respectively) to determinate the probability of a genotype originating from the population in which the individual was collected (Favre, Balloux, Goudet, & Perrin, 1997). Immigrants to a population, and therefore the dispersal sex, are expected to have lower mAIC and higher vAIC values than residents (Dubey, Brown, Madsen, & Shine, 2008; Goudet et al., 2002). All tests were performed based on 10,000 permutations.…”

Section: Methodsmentioning

confidence: 99%

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Patterns of population structure at microsatellite and mitochondrial DNA markers in the franciscana dolphin (Pontoporia blainvillei)

Gariboldi

Túnez

Failla³

et al. 2016

The franciscana dolphin, Pontorporia blainvillei, is an endemic cetacean of the Atlantic coast of South America. Its coastal distribution and restricted movement patterns make this species vulnerable to anthropogenic factors, particularly to incidental bycatch. We used mitochondrial DNA control region sequences, 10 microsatellites, and sex data to investigate the population structure of the franciscana dolphin from a previously established management area, which includes the southern edge of its geographic range. F‐statistics and Bayesian cluster analyses revealed the existence of three genetically distinct populations. Based on the microsatellite loci, similar levels of genetic variability were found in the area; 13 private alleles were found in Monte Hermoso, but none in Claromecó. When considering the mitochondrial DNA control region sequences, lower levels of genetic diversity were found in Monte Hermoso, when compared to the other localities. Low levels of gene flow were found between most localities. Additionally, no evidence of isolation by distance nor sex‐biased dispersal was detected in the study area. In view of these results showing that populations from Necochea/Claromecó, Monte Hermoso, and Río Negro were found to be genetically distinct and the available genetic information for the species previously published, Argentina would comprise five distinct populations: Samborombón West/Samborombón South, Cabo San Antonio/Buenos Aires East, Necochea/Claromecó/Buenos Aires Southwest, Monte Hermoso, and Río Negro. In order to ensure the long‐term survival of the franciscana dolphin, management and conservation strategies should be developed considering each of these populations as different management units.

“…Differences in philopatric behavior between the sexes may lead to a more pronounced genetic structure in the philopatric sex (Goudet, Perrin, & Waser, 2002; Podgórski et al., 2014; Storz, 1999). As females showed a higher level of genetic structure than males (significant F st , more genetic clusters, and significant spatial genetic structure), our results confirm the philopatric behavior of females (Dubois et al., 1992, 1994; Martins et al., 2002) and suggest that gene flow is essentially male‐biased in this population, as evidenced also in Bighorn sheep (Boyce et al., 1999).…”

Section: Discussionmentioning

confidence: 99%

Introduction history overrides social factors in explaining genetic structure of females in Mediterranean mouflon

Portanier

Garel

Devillard

et al. 2017

Fine‐scale spatial genetic structure of populations results from social and spatial behaviors of individuals such as sex‐biased dispersal and philopatry. However, the demographic history of a given population can override such socio‐spatial factors in shaping genetic variability when bottlenecks or founder events occurred in the population. Here, we investigated whether socio‐spatial organization determines the fine‐scale genetic structure for both sexes in a Mediterranean mouflon (Ovis gmelini musimon × Ovis sp.) population in southern France 60 years after its introduction. Based on multilocus genotypes at 16 loci of microsatellite DNA (n = 230 individuals), we identified three genetic groups for females and two for males, and concurrently defined the same number of socio‐spatial units using both GPS‐collared individuals (n = 121) and visual resightings of marked individuals (n = 378). The socio‐spatial and genetic structures did not match, indicating that the former was not the main driver of the latter for both sexes. Beyond this structural mismatch, we found significant, yet low, genetic differentiation among female socio‐spatial groups, and no genetic differentiation in males, with this suggesting female philopatry and male‐biased gene flow, respectively. Despite spatial disconnection, females from the north of the study area were genetically closer to females from the south, as indicated by the spatial analysis of the genetic variability, and this pattern was in accordance with the common genetic origin of their founders. To conclude, more than 14 generations later, genetic signatures of first introduction are not only still detectable among females, but they also represent the main factor shaping their present‐time genetic structure.