Pseudo-Random Mating with Multiple Alleles

The conditions on the mating matrix associated with a stable equilibrium are specified for an autosomal locus with four alleles. An example illustrates how Hardy–Weinberg proportions are maintained with nonrandom mating. The ABO blood group provides an illustration.

Sex-biased admixture and assortative mating shape genetic variation and influence demographic inference in admixed Cabo Verdeans

Genetic data can provide insights into population history, but first we must understand the patterns that complex histories leave in genomes. Here, we consider the admixed human population of Cabo Verde to understand the patterns of genetic variation left by social and demographic processes. First settled in the late 1400s, Cabo Verdeans are admixed descendants of Portuguese colonizers and enslaved West African people. We consider Cabo Verde′s well-studied historical record alongside genome-wide SNP data from 563 individuals from 4 regions within the archipelago. We use genetic ancestry to test for patterns of nonrandom mating and sex-specific gene flow, and we examine the consequences of these processes for common demographic inference methods and for genetic patterns. Notably, multiple population genetic tools that assume random mating underestimate the timing of admixture, but incorporating non-random mating produces estimates more consistent with historical records. We consider how admixture interrupts common summaries of genomic variation such as runs-of-homozygosity (ROH). While summaries of ROH may be difficult to interpret in admixed populations, differentiating ROH by length class shows that ROH reflect historical differences between the islands in their contributions from the source populations and post-admixture population dynamics. Finally, we find higher African ancestry on the X chromosome than on the autosomes, consistent with an excess of European males and African females contributing to the gene pool. Considering these genomic insights into population history in the context of Cabo Verde′s historical record, we can identify how assumptions in genetic models impact inference of population history more broadly.

Polymorphism of Growth Hormone (GH) Gene in Lakor Goat from Lakor Island of Southwest Maluku Regency

Lakor goat survive in Lakor island in Southwest Maluku with high temperature and limited water. Growth trait in goat is interest to explore cause related with economic trait that encoded by growth hormone (GH) gene. The aim of this study was identify of polymorphism GH gene of Lakor goat in Lakor island. A total of 63 samples were collected from three locations (village) i.e Ketti Letpey (18), Werwawan-Yamluli (26), and Letoda (19). DNA was extracted from hair follicles. A 422 bp specific DNA fragment was successfully amplified and genotyped by PCR-RFLP method using HaeIII enzyme. Results showed that polymorphism was found with two variant of genotypes (AA and AB) and two alleles (A and B). AB genotype was dominant in all of populations (93.7%) with A and B alleles were 0.53 and 0.47, respectively. Heterozygosity observed and expected value reached 0.502 and 0.498, respectively while Polymorphic Information Content was in moderate values (0.374). All of populations were in disequilibrium genetic. It maybe caused limited buck and nonrandom mating in population that effect of low genetic variation. Inbreeding study are needed to explore it. The introgression of bucks from other families in several locations within Lakor island can be an alternative solution to increase the genetic diversity of the lakor goat population.

Does Functionality Condition the Population Structure and Genetic Diversity of Endangered Dog Breeds under Island Territorial Isolation?

Despite the undefinition of the origins of Ca de Rater (CR) and Ca de Bestiar (CB) dogs, references to these endangered autochthonous breeds highlighted their ratting/pet and shepherding/guard skills for centuries. Genealogical historical records were traced back to founders. Founder number in the reference population (146 and 53 for CR and CB, respectively), historical and reference maximum generations traced (eight and seven for CR and CB, respectively), and historical average number of complete generations (1.04 for both breeds) were determined. Structure assessment revealed the existence of subpopulations regarding criteria such as breeders (75 and 17), breeder location (32 and eight), owners (368 and 198), and owner location (73 and 51) for CR and CB, respectively. Average inbreeding (F) within breed subpopulations ranged from 0.27–1.20% for CB breeders and the rest of subpopulation criteria for both breeds, respectively, except for CB owners and owner location. F ranged from 0.27–1.41% for CB historical population and CR current population, respectively. The study of genetic diversity revealed a relatively similar genetic background between subpopulations. Average coancestry between and within breeds suggested a similar evolutionary process. However, Mann–Whitney U test determined significant differences for diversity parameters (F, ΔR, coancestry, nonrandom mating degree, maximum, complete, and equivalent generations, ΔF, and genetic conservation index) between breeds and their functionalities. Conclusively, functionality in dog breeds may determine the genetic diversity evolution of endangered breeds, even when these share the same geographic isolation conditions.

Female toads engaging in adaptive hybridization prefer high-quality heterospecifics as mates

Hybridization—interbreeding between species—is generally thought to occur randomly between members of two species. Contrary to expectation, female plains spadefoot toads (Spea bombifrons) can increase their evolutionary fitness by preferentially mating with high-quality males of another species, the Mexican spadefoot toad (Spea multiplicata). Aspects of Mexican spadefoot males’ mating calls predict their hybrid offspring’s fitness, and plains spadefoot females prefer Mexican spadefoot males on the basis of these attributes, but only in populations and ecological conditions where hybridization is adaptive. By selecting fitness-enhancing mates of another species, females increase hybridization’s benefits and exert sexual selection across species. Nonrandom mating between species can thereby increase the potential for adaptive gene flow between species so that adaptive introgression is not simply happenstance.

Is there a host-associated molecular and morphological differentiation between sympatrically occurring individuals of the invasive leaf miner Cameraria ohridella?

The leaf-miner moth Cameraria ohridella, a pest in Central Europe, causes severe damage to trees. Host-associated differentiation (HAD) for this species has been suggested previously based on the occurrence of a specific mitochondrial haplotype. We assessed genetic diversity and population structure for sympatrically occurring individuals collected in association with two host species, Ohio buckeye (Aesculus glabra) and horse chestnut (Ae. hippocastanum), using six microsatellite loci (SSR) and mtDNA sequences that encode parts of cytochrome oxidase I and II. To infer population structure and assign individuals to clusters, we employed Bayesian clustering. We further characterized the relationships between genetic distance and geographical distance (IBD) in analyzed samples. Although our results derived from the SSR loci analyses demonstrating that there was no population substructuring caused by the hosts, we found evidence of differences in wing size, which might be attributed to the quality of food resources available to larvae. The population structure with K = 2 cannot be interpreted as the result of IBD; rather, it reflects a population differentiation due to demographic or genetic processes (e.g., an origin of invaders). Although genetic diversity was relatively high (He> 0.5), the population had a deficiency of heterozygotes (FIS > 0), which was most likely due to nonrandom mating and, possibly, a Wahlund effect. A star-like haplotype network and negative Tajima’s D support the genetic effect of bottleneck followed by population expansion. Based on presumably neutral markers, we conclude that C. ohridella appeared to be a good model for studying evolution toward a generalist invasive species, rather than HAD.

Patterns and drivers of genetic diversity and structure in the biological control parasitoid Habrobracon hebetor in Niger

When a promising natural enemy of a key pest exists locally, it is a common practice in biological control (BC) to rear and release it for supplementary control in the targeted agroecosystem even though significant knowledge gaps concerning pre/post release may still exist. Incorporating genetic information into BC research fills some of these gaps. Habrobracon hebetor, a parasitoid of many economically important moths that infest stored and field crops worldwide is commonly used, particularly against the millet head miner (MHM), a key pest of millet in Sahelian countries. To advance our knowledge on how H. hebetor that occurs naturally in open-field cropping systems and grain stores as well as being mass-produced and released for MHM control, performs in millet agroecosystems in Niger we evaluated its population genetics using two mitochondrial and 21 microsatellite markers. The field samples were genetically more diverse and displayed heterozygote excess. Very few field samples had faced significant recent demographic bottlenecks. The mating system (i.e. nonrandom mating with complementary sex determination) of this species may be the major driver of these findings rather than bottlenecks caused by the small number of individuals released and the scarcity of hosts during the longlasting dry season in Niger. H. hebetor population structure was represented by several small patches and genetically distinct individuals. Gene flow occurred at local and regional scales through human-mediated and natural short-distance dispersal. These findings highlight the importance of the mating system in the genetic diversity and structure of H. hebetor populations, and contribute to our understanding of its reported efficacy against MHM in pearl millet fields.