Microsatellite marker set for genetic diversity assessment of primitive Chitala chitala (Hamilton, 1822) derived through SMRT sequencing technology

Microsatellite Genome-Wide Database Development for the Commercial Blackhead Seabream (Acanthopagrus schlegelii)

Simple sequence repeats (SSRs), the markers with the highest polymorphism and co-dominance degrees, offer a crucial genetic research resource. Limited SSR markers in blackhead seabream have been reported. The availability of the blackhead seabream genome assembly provided the opportunity to carry out genome-wide identification for all microsatellite markers, and bioinformatic analyses open the way for developing a microsatellite genome-wide database in blackhead seabream. In this study, a total of 412,381 SSRs were identified in the 688.08 Mb genome by Krait software. Whole-genome sequences (10×) of 42 samples were aligned against the reference genome and genotyped using the HipSTR tools by comparing and counting repeat number variation across the SSR loci. A total of 156,086 SSRs with a 2–4 bp repeat were genotyped by HipSTR tools, which accounted for 55.78% of the 2–4 bp SSRs in the reference genome. High accuracy of genotyping was observed by comparing HipSTR tools and PCR amplification. A set of 109,131 loci with a number of alleles ≥ 3 and with a number of genotyped individuals ≥ 6 were reserved to constitute the polymorphic SSR database. Fifty-one polymorphic SSR loci were identified through PCR amplification. This strategy to develop polymorphic SSR markers not only obtained a large set of polymorphic SSRs but also eliminated the need for laborious experimental screening. SSR markers developed in this study may facilitate blackhead seabream research, which lays a certain foundation for further gene tagging and genetic linkage analysis, such as marker-assisted selection, genetic mapping, as well as comparative genomic analysis.

First microsatellite markers for the European Robin (Erithacus rubecula) and their application in analysis of parentage and genetic diversity

The European Robin is a small passerine bird associated with woodlands of Eurasia and North Africa. Despite being relatively widespread and common, little is known of the species’ breeding biology and genetic diversity. We used Next Generation Sequencing (NGS) to develop and characterize microsatellite markers for the European Robin, designing three multiplex panels to amplify 14 microsatellite loci. The level of polymorphism and its value for assessing parentage and genetic structure was estimated based on 119 individuals, including seven full families and 69 unrelated individuals form Poland’s Białowieża Primaeval Forest and an additional location in Portugal. All markers appeared to be highly variable. Analysis at the family level confirmed a Mendelian manner of inheritance in the investigated loci. Genetic data also revealed evidence for extra-pair paternity in one family. The set of markers that we developed are proven to be valuable for analysis of the breeding biology and population genetics of the European Robin.

Characterization of novel genotyping-by-sequencing (GBS)-based simple sequence repeats (SSRs) and their application for population genomics of Capoeta aculeata (Valenciennes, 1844)

BACKGROUND

The species Capoeta aculeata (Valenciennes, 1844) is one of the most important freshwater species endemic to Iran. However, the investigation of the population genetic structure of this species is limited by the low number of molecular markers currently described.

METHODS AND RESULTS

In this study, we implemented next generation sequencing technology to identify polymorphic microsatellite markers and investigate the population genetic structure of C. aculeata sampled from three geographical sites in Iran. We characterized and developed 36 novel polymorphic microsatellite markers and these loci were examined in 120 individuals from three populations occurring in the Zagros basin. The average number of alleles per locus varied from 1.7 to 16 (average = 7.89). The results showed that, the polymorphism information content (PIC) of these simple sequence repeat (SSR) loci varied from 0.254 to 0.888. The observed heterozygosity (H_O) per locus ranged from 0.170 to 0.881, while the expected heterozygosity (H_E) per locus was from 0.170 to 0.881. Among these SSR loci, 20 loci deviated significantly from the Hardy-Weinberg equilibrium after Bonferroni correction (p < 0.05).

CONCLUSIONS

These microsatellite markers could provide a valuable tool for future population and conservation genetics studies of C. aculeate and other closely related species.

Development of microsatellite loci and optimization of a multiplex assay for Latibulus argiolus (Hymenoptera: Ichneumonidae), the specialized parasitoid of paper wasps

Microsatellite loci are commonly used markers in population genetic studies. In this study, we present 40 novel and polymorphic microsatellite loci elaborated for the ichneumonid parasitoid Latibulus argiolus (Rossi, 1790). Reaction condition optimisation procedures allowed 14 of these loci to be co-amplified in two PCRs and loaded in two multiplex panels onto a genetic analyser. The assay was tested on 197 individuals of L. argiolus originating from ten natural populations obtained from the host nests of paper wasps. The validated loci were polymorphic with high allele numbers ranging from eight to 27 (average 17.6 alleles per locus). Both observed and expected heterozygosity values were high, ranging between 0.75 and 0.92 for H_O (mean 0.83) and from 0.70 to 0.90 for H_E (mean 0.85). The optimized assay showed low genotyping error rate and negligible null allele frequency. The designed multiplex panels could be successfully applied in relatedness analyses and genetic variability studies of L. argiolus populations, which would be particularly interesting considering the coevolutionary context of this species with its social host.