Transferability of heterologous microsatellite primers in Brycon gouldingi

Abstract

Brycon gouldingi is a species of neotropical fish of socioeconomic and environmental importance in the Tocantins-Araguaia Basin. Genetic studies on this species are still limited, making it difficult to evaluate the population structure and genetic diversity in natural and captive stocks. Here, we aimed to evaluate the transferability of heterologous microsatellite primers in B. gouldingi. A total of 30 primers for eight species were evaluated: Brycon hilarii, Brycon opalinus, Brycon cephalus, Brycon orbignyanus, Prochilodus lineatus, Prochilodus argenteus, Piaractus mesopotamicus, and Colossoma macropomum. The primers that showed the best amplification patterns were applied to 20 specimens of B. gouldingi, and their genetic parameters were assessed. Among the 30 primers, seven showed satisfactory transferability, six of which belonged to the genus Brycon: Bh13 (B. hilarii), BoM5, BoM13 (B. opalinus), Borg9, Borg13, and Borg59 (B. orbignyanus), and one belonged to P. argenteus (Par80). The primers for the other species tested showed non-specificity or monomorphism; and were therefore, excluded from the analyses. The number of alleles ranged between two (Borg13 and Borg59) and three (Bh13, BoM5, BoM13, Borg9 and Par80), with sizes varying between 103 bp (BoM5) and 430 bp (Borg9). Four primers showed evidence of null alleles (BoM13, Borg9, Borg13, and Par80), which could probably be attributed to the respective Hardy-Weinberg deviation. Thus, seven primers were validated for cross-amplification in B. gouldingi, which may be used in future studies involving this species.

Transferability of heterologous primers in Brycon falcatus

“…According to the authors, the Rio Verde population presented satisfactory genetic variability. A B. gouldingi population of the Araguaia River (Souza et al 2018b) had lower Ho (0.157) and He (0.357) than those found for B. falcatus in our study. Our results demonstrate a moderate genetic variability in the B. falcatus population.…”

“…The number of alleles per locus in most primers was similar to that found by Castro et al (2017) in cross-amplification of microsatellite markers of B. hilarii and B. opalinus in B. orbignyans; and similar to that found by Souza et al (2018b) in cross-amplification of microsatellite of B. hilarii, B. opalinus and B. orbignyanus in B. goudingi. In a study with natural populations of Prochilodus lineatus, Lopera- Barrero et al (2016b) found a variation of three to six alleles produced by the Par12 locus and three to five alleles produced by the Par80 locus.…”

“…Cross amplification in related species increases the frequency of these alleles as the phylogenetic distance between species increases (Chapuis and Estoup 2007). This has already been demonstrated in the transferability of B. orbignyanus, B. opalinus and P. argenteus microsatellite primers in B. gouldingi (Souza et al 2018b), and B. opalinus primers in B. orbignyanus (Ashikaga et al 2015). In the latter study, the authors attributed the deviation in the Hardy-Weinberg equilibrium in some loci of natural populations of B. orbignyanus to the high frequency of these alleles.…”

“…The presence of null alleles in microsatellite markers is apparently recurrent in population studies in fish (Ashikaga et al, 2015;Henriques et al, 2017;Souza et al, 2018b).…”

Transferability of heterologous microsatellite primers in Leiarius marmoratus

“…In general, primers of species with phylogenetic proximity are used, and generally the primers with the highest reproducibility are those from species belonging to the same genus or family (Carmo, Polo, Silva, & Yazbeck., 2015;Castro et al, 2017;Lima et al, 2008). Some studies have demonstrated the efficiency of cross-amplification in Brazilian native fish species, such as Brycon orbignyanus (Carmo et al, 2015), Brycon gouldingi (Souza et al, 2018a), Leporinus elongatus, Rhamdia quelen (Lopera-Barrero et al, 2016), and Colossoma macropomum (Lima et al, 2008). However, the lack of characterization of specific molecular markers or studies with transferability of microsatellite primers in L. marmoratus limits genetic studies on this species.…”