Population Genetic Parameters Research Articles

The analysis of FSH beta-subunit gene genotypes in East Anatolian Red, East Anatolian Red×Holstein, and Zavot bulls

Abstract This study aimed to investigate the genotypic distribution and population genetic parameters of the single nucleotide polymorphism (SNP) located on exon 3 at the FSHB gene in East Anatolian Red (EAR), East Anatolian Red×Holstein (EAR×H), and Zavot (Z) bulls. A total of 68 cattle including EAR (n=34), EAR×H (n=20), and Z (n=14) bulls were used. Genomic DNA was isolated from blood samples using the phenol/chloroform method. The genotyping of the SNP was carried out by the PCR-RFLP using the PstI restriction enzyme. Deviation from Hardy–Weinberg equilibrium (HWE) was calculated by using the chi-square goodness-of-fit test. Population genetics evaluation was performed for effective allele numbers, the polymorphism information content, theoretical heterozygosity, the fixation index, level of possible variability realization, and the Shannon-Weaver diversity index. In the present study, the AA and the AB genotypes were predominant in EAR and EAR×H bulls, respectively. Zavot breed was found to be monomorphic. There was a deviation from HWE, concerning the total cattle population. The population genetics evaluation showed that the marker was moderately informative for EAR and the crossbreeds, as well as the total population. Consequently, the polymorphism (rs207774587) within exon 3 of the bovine FSHB can be interpreted as a genetic marker with reliable variability for EAR and the crossbreeds, but not in Zavot cattle.

DISTRIBUTION OF MTHFR C677T GENE POLYMORPHISM IN HEALTHY NORTH MACEDONIAN POPULATION

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme of folate pathway and mutation of the enzyme methylentetrahydrofolate reductase MTHFR C677T gene. But whether it has influence on the level of total homocysteine is still under debate. Several polymorphisms have been reported in MTHFR gene, but C677T polymorphism is the most studied and it has been reported to be a risk factor for several diseases/disorders. Also, extensive studies have been conducted in various ethnic groups. The present study was designed to explore the frequency of MTHFR C677T polymorphism in North Macedonian healthy population. The study group consisted of 123 healthy subjects, benevolent blood donors, who were declared to be healthy by a medical doctor from the National Institute for Transfusion Medicine in R.  N. Macedonia. The MTHFR gene polymorphism was analyzed by the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Our analysis showed that the measurement of the population-genetic parameters of the allelic frequency at the T variable nucleotide had the allelic frequency 0.314. The global prevalence of TT genotype was Hardy - Weinberg's custom with a p value of 0.866, which was excluded from the x2test. The remaining parameters, however, indicated the genetically balanced population and they were important for the reliability of the analysis. In the Macedonian population T variant of the allele has the opposite frequency, but the lowest frequency has the genotype TT. Keywords: mutation of methylentetrahydrofolate reductase, frequency, Macedonian population  

Изменчивость признаков вегетативных органов лиственницы Гмелина в Забайкальском крае

Изменчивость признаков вегетативных органов лиственницы Гмелина в Забайкальском крае

Análisis del pedigrí en diez poblaciones mexicanas de ovinos

Se analizó el pedigrí en diez razas de ovinos mediante parámetros genéticos poblacionales. Las poblaciones fueron Blackbelly (BBL; 19,695), Charollais (CHA; 5,033), Dorper (DOR; 42,171), Dorper Blanco (DOB; 4,213), Dorset (DOS; 5,557), Hampshire (HAM; 12,210), Katahdin (KAT; 77,955), Pelibuey (PEL; 42,256), Rambouillet (RAM; 11,951) y Suffolk (SUF; 14,099); nacidos de 1992 a 2018. Los análisis se realizaron con el software Endog. En padres conocidos, los valores oscilaron de 76.4 % (SUF) a 95.3 % (KAT), con promedio general de 86.0%, los animales con padres desconocidos correspondieron a los fundadores. La población consanguínea (como porcentaje de la población total) fluctuó del 12.3 % en DOS al 48.7 % en DOB, con promedio general de 29.7 %; la consanguinidad (F) promedio osciló de 3.9 (KAT) a 14.6 (DOB), con promedio general de 8.0. La evolución de F y sus componentes fue: en todas las poblaciones, la proporción de consanguíneos se incrementó (P<0.05); los niveles de relación genética (RG) son estables; y, la F presentó tendencias negativas (P<0.05). KAT, DOB y BBL con altas tasas de crecimiento en población consanguínea; DOB y DOS, DOB y CHA con los niveles más altos de F y RG, respectivamente. Seis poblaciones presentaron tamaño efectivo (Ne) mayor a 50; el resto presentaron Ne menor a 37, lo cual señala el estatus de cuidado para monitorear la evolución de F y sus posibles implicaciones. El intervalo generacional (IG) osciló de 3.0 a 4.15, con promedio general de 3.45 años, los mayores IG fueron para RAM y SUF, BBL y DOR con IG menores.

Tomato Yellow Leaf Curl Virus-Resistant and -Susceptible Tomato Genotypes Similarly Impact the Virus Population Genetics.

Tomato yellow leaf curl virus is a species in the genus Begomovirus and family Geminiviridae. Tomato yellow leaf curl virus (TYLCV) infection induces severe symptoms on tomato plants and causes serious yield losses worldwide. TYLCV is persistently transmitted by the sweetpotato whitefly, Bemisia tabaci (Gennadius). Cultivars and hybrids with a single or few genes conferring resistance against TYLCV are often planted to mitigate TYLCV-induced losses. These resistant genotypes (cultivars or hybrids) are not immune to TYLCV. They typically develop systemic infection, display mild symptoms, and produce more marketable tomatoes than susceptible genotypes under TYLCV pressure. In several pathosystems, extensive use of resistant cultivars with single dominant resistance-conferring gene has led to intense selection pressure on the virus, development of highly virulent strains, and resistance breakdown. This study assessed differences in TYLCV genomes isolated from susceptible and resistant genotypes in Florida and Georgia. Phylogenetic analyses indicated that Florida and Georgia isolates were distinct from each other. Population genetics analyses with genomes field-collected from resistant and susceptible genotypes from Florida and/or Georgia provided no evidence of a genetic structure between the resistant and susceptible genotypes. No codons in TYLCV genomes from TYLCV-resistant or susceptible genotypes were under positive selection, suggesting that highly virulent or resistance-breaking TYLCV strains might not be common in tomato farmscapes in Florida and Georgia. With TYLCV-resistant genotypes usage increasing recently and multiple tomato crops being planted during a calendar year, host resistance-induced selection pressure on the virus remains a critical issue. To address the same, a greenhouse selection experiment with one TYLCV-resistant and susceptible genotype was conducted. Each genotype was challenged with TYLCV through whitefly-mediated transmission serially 10 times (T1-T10). Population genetics parameters at the genome level were assessed at T1, T5, and T10. Results indicated that genomes from resistant and susceptible genotypes did not differentiate with increasing transmission number, no specific mutations were repeatedly observed, and no positive selection was detected. These results reiterate that resistance in tomato might not be exerting selection pressure against TYLCV to facilitate development of resistance-breaking strains. TYLCV populations rather seem to be shaped by purifying selection and/or population expansion.

The geometry and genetics of hybridization.

When divergent populations form hybrids, hybrid fitness can vary with genome composition, current environmental conditions, and the divergence history of the populations. We develop analytical predictions for hybrid fitness, which incorporate all three factors. The predictions are based on Fisher's geometric model, and apply to a wide range of population genetic parameter regimes and divergence conditions, including allopatry and parapatry, local adaptation, and drift. Results show that hybrid fitness can be decomposed into intrinsic effects of admixture and heterozygosity, and extrinsic effects of the (local) adaptedness of the parental lines. Effect sizes are determined by a handful of geometric distances, which have a simple biological interpretation. These distances also reflect the mode and amount of divergence, such that there is convergence toward a characteristic pattern of intrinsic isolation. We next connect our results to the quantitative genetics of line crosses in variable or patchy environments. This means that the geometrical distances can be estimated from cross data, and provides a simple interpretation of the “composite effects.” Finally, we develop extensions to the model, involving selectively induced disequilibria, and variable phenotypic dominance. The geometry of fitness landscapes provides a unifying framework for understanding speciation, and wider patterns of hybrid fitness.

Geographical pattern of genetic diversity in Capsella bursa-pastoris (Brassicaceae)-A global perspective.

We analyzed the global genetic variation pattern of Capsella bursa‐pastoris (Brassicaceae) as expressed in allozymic (within‐locus) diversity and isozymic (between‐locus) diversity. Results are based on a global sampling of more than 20,000 C. bursa‐pastoris individuals randomly taken from 1,469 natural provenances in the native and introduced range, covering a broad spectrum of the species’ geographic distribution. We evaluated data for population genetic parameters and F‐statistics, and Mantel tests and AMOVA were performed. Geographical distribution patterns of alleles and multilocus genotypes are shown in maps and tables. Genetic diversity of introduced populations is only moderately reduced in comparison with native populations. Global population structure was analyzed with structure, and the obtained cluster affiliation was tested independently with classification approaches and macroclimatic data using species distribution modeling. Analyses revealed two main clusters: one distributed predominantly in warm arid to semiarid climate regions and the other predominantly in more temperate humid to semihumid climate regions. We observed admixture between the two lineages predominantly in regions with intermediate humidity in both the native and non‐native ranges. The genetically derived clusters are strongly supported in macroclimatic data space. The worldwide distribution patterns of genetic variation in the range of C. bursa‐pastoris can be explained by intensive intra‐ and intercontinental migration, but environmental filtering due to climate preadaption seems also involved. Multiple independent introductions of genotypes from different source regions are obvious. “Endemic” genotypes might be the outcome of admixture or of de novo mutation. We conclude that today's successfully established Capsella genotypes were preadapted and found matching niche conditions in the colonized range parts.

Distance metrics for ranked evolutionary trees

Genealogical tree modeling is essential for estimating evolutionary parameters in population genetics and phylogenetics. Recent mathematical results concerning ranked genealogies without leaf labels unlock opportunities in the analysis of evolutionary trees. In particular, comparisons between ranked genealogies facilitate the study of evolutionary processes of different organisms sampled at multiple time periods. We propose metrics on ranked tree shapes and ranked genealogies for lineages isochronously and heterochronously sampled. Our proposed tree metrics make it possible to conduct statistical analyses of ranked tree shapes and timed ranked tree shapes or ranked genealogies. Such analyses allow us to assess differences in tree distributions, quantify estimation uncertainty, and summarize tree distributions. We show the utility of our metrics via simulations and an application in infectious diseases.

Genetic Polymorphism of 15 Autosomal STR loci in Population of Madhya Pradesh

We report here an autosomal STR DNA database of Population of Madhya Pradesh and evaluation ofautosomal STR diversity in the context of population genetics and forensic efficiency parameters. In thisstudy, Allele frequencies of 15 autosomal STR loci were investigated in 123 unrelated individuals (57 Female& 66 Male) from the various geographical regions of Madhya Pradesh using PowerPlex® 16 HS System.All the studied loci appeared the high degree of genetic polymorphism with observed Heterozygosity (Ho=observed heterozygosity) ranged from 0.911 (D21S11) to 0.659 (TPOX). Locus PENTA E showed the highestpower of discrimination (0.978) and the highest polymorphism (PIC = 0.90). The combined probability ofmatch (CPM) and combined paternity Index (CPI) for all the 15 STR loci was found to be 2.8 x 10-18 and 1.2x106, respectively. The combined discrimination power (CPD) and combined exclusion power (CPE) for allthe tested 15 Loci was observed 1 and 0.9999989 respectively, assign that all the loci are highly polymorphicand have the potential for forensic application.

On the estimation of inbreeding depression using different measures of inbreeding from molecular markers.

The inbreeding coefficient (F) of individuals can be estimated from molecular marker data, such as SNPs, using measures of homozygosity of individual markers or runs of homozygosity (ROH) across the genome. These different measures of F can then be used to estimate the rate of inbreeding depression (ID) for quantitative traits. Some recent simulation studies have investigated the accuracy of this estimation with contradictory results. Whereas some studies suggest that estimates of inbreeding from ROH account more accurately for ID, others suggest that inbreeding measures from SNP‐by‐SNP homozygosity giving a large weight to rare alleles are more accurate. Here, we try to give more light on this issue by carrying out a set of computer simulations considering a range of population genetic parameters and population sizes. Our results show that the previous studies are indeed not contradictory. In populations with low effective size, where relationships are more tight and selection is relatively less intense, F measures based on ROH provide very accurate estimates of ID whereas SNP‐by‐SNP‐based F measures with high weight to rare alleles can show substantial upwardly biased estimates of ID. However, in populations of large effective size, with more intense selection and trait allele frequencies expected to be low if they are deleterious for fitness because of purifying selection, average estimates of ID from SNP‐by‐SNP‐based F values become unbiased or slightly downwardly biased and those from ROH‐based F values become slightly downwardly biased. The noise attached to all these estimates, nevertheless, can be very high in large‐sized populations. We also investigate the relationship between the different F measures and the homozygous mutation load, which has been suggested as a proxy of inbreeding depression.

Monitoring Plasmodium falciparum and Plasmodium vivax using microsatellite markers indicates limited changes in population structure after substantial transmission decline in Papua New Guinea.

Monitoring the genetic structure of pathogen populations may be an economical and sensitive approach to quantify the impact of control on transmission dynamics, highlighting the need for a better understanding of changes in population genetic parameters as transmission declines. Here we describe the first population genetic analysis of two major human malaria parasites, Plasmodium falciparum (Pf) and Plasmodium vivax (Pv), following nationwide distribution of long-lasting insecticide-treated nets (LLINs) in Papua New Guinea (PNG). Parasite isolates from pre- (2005-2006) and post-LLIN (2010-2014) were genotyped using microsatellite markers. Despite parasite prevalence declining substantially (East Sepik Province: Pf=54.9%-8.5%, Pv=35.7%-5.6%, Madang Province: Pf=38.0%-9.0%, Pv: 31.8%-19.7%), genetically diverse and intermixing parasite populations remained. Pf diversity declined modestly post-LLIN relative to pre-LLIN (East Sepik: Rs =7.1-6.4, HE =0.77-0.71; Madang: Rs =8.2-6.1, HE =0.79-0.71). Unexpectedly, population structure present in pre-LLIN populations was lost post-LLIN, suggesting that more frequent human movement between provinces may have contributed to higher gene flow. Pv prevalence initially declined but increased again in one province, yet diversity remained high throughout the study period (East Sepik: Rs =11.4-9.3, HE =0.83-0.80; Madang: Rs =12.2-14.5, HE =0.85-0.88). Although genetic differentiation values increased between provinces over time, no significant population structure was observed at any time point. For both species, a decline in multiple infections and increasing clonal transmission and significant multilocus linkage disequilibrium post-LLIN were positive indicators of impact on the parasite population using microsatellite markers. These parameters may be useful adjuncts to traditional epidemiological tools in the early stages of transmission reduction.

Detecting and Quantifying Natural Selection at Two Linked Loci from Time Series Data of Allele Frequencies with Forward-in-Time Simulations.

Recent advances in DNA sequencing techniques have made it possible to monitor genomes in great detail over time. This improvement provides an opportunity for us to study natural selection based on time serial samples of genomes while accounting for genetic recombination effect and local linkage information. Such time series genomic data allow for more accurate estimation of population genetic parameters and hypothesis testing on the recent action of natural selection. In this work, we develop a novel Bayesian statistical framework for inferring natural selection at a pair of linked loci by capitalising on the temporal aspect of DNA data with the additional flexibility of modeling the sampled chromosomes that contain unknown alleles. Our approach is built on a hidden Markov model where the underlying process is a two-locus Wright-Fisher diffusion with selection, which enables us to explicitly model genetic recombination and local linkage. The posterior probability distribution for selection coefficients is computed by applying the particle marginal Metropolis-Hastings algorithm, which allows us to efficiently calculate the likelihood. We evaluate the performance of our Bayesian inference procedure through extensive simulations, showing that our approach can deliver accurate estimates of selection coefficients, and the addition of genetic recombination and local linkage brings about significant improvement in the inference of natural selection. We also illustrate the utility of our method on real data with an application to ancient DNA data associated with white spotting patterns in horses.

Estimation of Natural Selection and Allele Age from Time Series Allele Frequency Data Using a Novel Likelihood-Based Approach.

Temporally spaced genetic data allow for more accurate inference of population genetic parameters and hypothesis testing on the recent action of natural selection. In this work, we develop a novel likelihood-based method for jointly estimating selection coefficient and allele age from time series data of allele frequencies. Our approach is based on a hidden Markov model where the underlying process is a Wright-Fisher diffusion conditioned to survive until the time of the most recent sample. This formulation circumvents the assumption required in existing methods that the allele is created by mutation at a certain low frequency. We calculate the likelihood by numerically solving the resulting Kolmogorov backward equation backward in time while reweighting the solution with the emission probabilities of the observation at each sampling time point. This procedure reduces the two-dimensional numerical search for the maximum of the likelihood surface, for both the selection coefficient and the allele age, to a one-dimensional search over the selection coefficient only. We illustrate through extensive simulations that our method can produce accurate estimates of the selection coefficient and the allele age under both constant and nonconstant demographic histories. We apply our approach to reanalyze ancient DNA data associated with horse base coat colors. We find that ignoring demographic histories or grouping raw samples can significantly bias the inference results.

Forensic application and genetic diversity of 21 autosomal STR loci in five major population groups of Pakistan.

Investigation of genetic diversity of the 21 autosomal STR loci included in the GlobalFilerTM PCR Amplification Kit in 529 Pakistani individuals belonging to the Punjabi, Pashtun, Sindhi, Saraiki, and Baloch ethnic groups. Population genetic parameters and forensic informative metrics for each group were evaluated. SE33 showed the greatest power of discrimination in all populations studied. The combined match probability ranged from 8.06E-27 (Saraiki) to 1.05E-26 (Baloch), and the combined power of exclusion ranged from 0.99999999902 (Punjabi) to 0.99999999964 (Pashtun). D12S391 in the Baloch population and D2S441 in the Saraiki population showed deviation from Hardy-Weinberg equilibrium. Significant genetic distances were observed between the Punjabi, Pashtun, and Baloch populations. This study supports the utilization of the GlobalFilerTM STR kit for forensic applications in Pakistan.

Evaluation of the Minimum Sampling Design for Population Genomic and Microsatellite Studies: An Analysis Based on Wild Maize.

Massive parallel sequencing (MPS) is revolutionizing the field of molecular ecology by allowing us to understand better the evolutionary history of populations and species, and to detect genomic regions that could be under selection. However, the economic and computational resources needed generate a tradeoff between the amount of loci that can be obtained and the number of populations or individuals that can be sequenced. In this work, we analyzed and compared two simulated genomic datasets fitting a hierarchical structure, two extensive empirical genomic datasets, and a dataset comprising microsatellite information. For all datasets, we generated different subsampling designs by changing the number of loci, individuals, populations, and individuals per population to test for deviations in classic population genetics parameters (HS, FIS, FST). For the empirical datasets we also analyzed the effect of sampling design on landscape genetic tests (isolation by distance and environment, central abundance hypothesis). We also tested the effect of sampling a different number of populations in the detection of outlier SNPs. We found that the microsatellite dataset is very sensitive to the number of individuals sampled when obtaining summary statistics. FIS was particularly sensitive to a low sampling of individuals in the simulated, genomic, and microsatellite datasets. For the empirical and simulated genomic datasets, we found that as long as many populations are sampled, few individuals and loci are needed. For the empirical datasets, we found that increasing the number of populations sampled was important in obtaining precise landscape genetic estimates. Finally, we corroborated that outlier tests are sensitive to the number of populations sampled. We conclude by proposing different sampling designs depending on the objectives.

Comparisons of sampling methods for assessing intra- and inter-accession genetic diversity in three rice species using genotyping by sequencing

To minimize the cost of sample preparation and genotyping, most genebank genomics studies in self-pollinating species are conducted on a single individual to represent an accession, which may be heterogeneous with larger than expected intra-accession genetic variation. Here, we compared various population genetics parameters among six DNA (leaf) sampling methods on 90 accessions representing a wild species (O. barthii), cultivated and landraces (O. glaberrima, O. sativa), and improved varieties derived through interspecific hybridizations. A total of 1,527 DNA samples were genotyped with 46,818 polymorphic single nucleotide polymorphisms (SNPs) using DArTseq. Various statistical analyses were performed on eleven datasets corresponding to 5 plants per accession individually and in a bulk (two sets), 10 plants individually and in a bulk (two sets), all 15 plants individually (one set), and a randomly sampled individual repeated six times (six sets). Overall, we arrived at broadly similar conclusions across 11 datasets in terms of SNP polymorphism, heterozygosity/heterogeneity, diversity indices, concordance among genetic dissimilarity matrices, population structure, and genetic differentiation; there were, however, a few discrepancies between some pairs of datasets. Detailed results of each sampling method, the concordance in their outputs, and the technical and cost implications of each method were discussed.

Genetic Polymorphism and Forensic Application of 47 Autosomal InDel Loci in 5 Chinese Ethnic Groups.

Objective To investigate the population genetic data of 47 autosomal insertion/deletion （InDel） polymorphism genetic markers involved in AGCU InDel 50 kit in Guangdong Han, Guangxi Zhuang, Guangxi Yao, Guangxi Jing, and Guangxi Mulam, and to evaluate their application in forensic DNA identification. Methods Multiplex amplification of the 768 unrelated individuals from the 5 ethnic groups mentioned above was performed with the AGCU InDel 50 kit. Genotyping was carried out by 3500xL gene analyzer, population genetic parameters were gathered and polymorphism analysis was performed. Results No linkage disequilibrium was found among 47 autosomal InDel loci in the 5 ethnic groups. The distribution of genotype frequency of 47 autosomal InDel loci confirmed to the Hardy-Weinberg equilibrium in Guangdong Han and Guangxi Zhuang. Except for rs139934789, the other 46 loci confirmed to the Hardy-Weinberg equilibrium in Guangxi Yao, Guangxi Jing, and Guangxi Mulam. The results of genetic variation analysis among the populations showed that 1.12% of genetic variation was caused by ethnic group differences. The cumulative discrimination power of 47 autosomal InDel loci for the 5 ethnic groups were all above 0.999 999 999 999 999. The cumulative probability of exclusion for each ethnic group was less than 0.999 9. The two Y-InDels were identified in all male individuals and were absent in all female individuals. Conclusion Except for rs139934789, the other 46 InDel loci have a relatively good genetic polymorphism in the 5 Chinese ethnic groups, and can be used for forensic individual identification and as effective supplements for paternity testing.

Establishment of DNA fingerprints for Chrysosplenium using SRAP Markers

As a traditional Chinese medicinal material, Chrysosplenium is urgently needed for genetic resource investigation and protection research due to the decrease of its wild resources in recent years. After investigating the wild resources, we conducted genetic polymorphism and clustering studies of 24 species(a total of 36 samples) of Chrysosplenium using SRAP technique. The results showed that a total of 374 polymorphic bands were obtained using 18 pairs of SRAP primers to amplify these samples, on average of 20.7 bands for each primer pair. We used the biological software to analyze the population's genetic parameter and got the N_a value as 2.000 0, N_(e )value as 1.408 4, the average Nei's index as 0.263 5, and the average Shannon information index as 0.419 1. UPGMA cluster analysis showed that all the samples can be divided into three major groups at the genetic similarity coefficient of 0.70: there are 18 species(24 samples) gathered for the Ⅰ groups, 3 species or variation(7 samples) for Ⅱ groups, and 3 species(5 samples) for Ⅲ groups. The differences of these Chrysosplenium species at the molecular level are consistent with that of their geographical and ecological distribution. At the same time, we used SRAP technology to construct 36 DNA digital fingerprints of Chrysosplenium and obtained the unique molecular identification band type of each material. These results will provide effective methods and reliable basis for the identification, protection and genetic diversity analysis of the germplasm resources of Chrysosplenium, and lay a foundation for the further development and utilization of them.

Temporal migration rates affect the genetic structure of populations in the biennial Erysimum mediohispanicum with reproductive asynchrony.

Migration is a process with important implications for the genetic structure of populations. However, there is an aspect of migration seldom investigated in plants: migration between temporally isolated groups of individuals within the same geographic population. The genetic implications of temporal migration can be particularly relevant for semelparous organisms, which are those that reproduce only once in a lifetime after a certain period of growth. In this case, reproductive asynchrony in individuals of the same population generates demes of individuals differing in their developmental stage (non-reproductive and reproductive). These demes are connected by temporal migrants, that is, individuals that become annually asynchronous with respect to the rest of individuals of their same deme. Here, we investigated the extent of temporal migration and its effects on temporal genetic structure in the biennial plant Erysimum mediohispanicum. To this end, we conducted two independent complementary approaches. First, we empirically estimated temporal migration rates and temporal genetic structure in four populations of E. mediohispanicum during three consecutive years using nuclear microsatellites markers. Second, we developed a demographic genetic simulation model to assess genetic structure for different migration scenarios differing in temporal migration rates and their occurrence probabilities. We hypothesized that genetic structure decreased with increasing temporal migration rates due to the homogenizing effect of migration. Empirical and modelling results were consistent and indicated a U-shape relationship between genetic structure and temporal migration rates. Overall, they indicated the existence of temporal genetic structure and that such genetic structure indeed decreased with increasing temporal migration rates. However, genetic structure increased again at high temporal migration rates. The results shed light into the effects of reproductive asynchrony on important population genetic parameters. Our study contributes to unravel the complexity of some processes that may account for genetic diversity and genetic structure of natural populations.

Genetic and phenotypic consequences of early domestication in black soldier flies (Hermetia illucens)

The black soldier fly, Hermetia illucens, is an emerging biotechnological agent with its larvae being effective converters of organic waste into usable bio-products including protein and lipids. To date, most operations use unimproved commercial populations produced by mass rearing, without cognisance of specific breeding strategies. The genetic and phenotypic consequences of these commercial practices remain unknown and could have a significant impact on long-term population viability and productivity. The aim of this study was thus to assess the genetic and phenotypic changes during the early phases of colony establishment and domestication in the black soldier fly. An experimental colony was established from wild founder flies and a new microsatellite marker panel was developed to assess population genetic parameters along with the phenotypic characteristics of each generational cohort under captive breeding. The experimental colony was characterised by a small effective population size, subsequent loss of genetic diversity and rapid genetic and phenotypic differentiation between the generational cohorts. Ultimately, the population collapsed by the fifth generation, most likely owing to the adverse effect of inbreeding depression following the fixation of deleterious alleles. Species with r-selected life history characteristics (e.g. short life-span, high fecundity and low larval survival) are known to pose particular challenges for genetic management. The current study suggests that sufficient genetic and phenotypic variations exist in the wild population and that domestication and strain development could be achieved with careful population augmentation and selection during the early stages of colony establishment.