Evidence of facultative parthenogenesis in three Neotropical pitviper species of the Bothrops atrox group

PeerJ. 2020 Nov 18:8:e10097. doi: 10.7717/peerj.10097. eCollection 2020.

Abstract

We examined four suspected cases of facultative parthenogenesis in three species of a neotropical lineage of pitvipers of the Bothrops atrox group. Reproduction without mating was observed in captive females of B. atrox, B. moojeni and B. leucurus housed alone for seven years (the two former species) and nine years (the latter one). In addition to the observation of captivity data, we investigated molecularly this phenomenon using heterologous microsatellites. DNA was extracted from the mothers' scales or liver, from embryo and newborn fragments, and yolked ova. Four of the microsatellites showed good amplification using Polymerase Chain Reaction and informative band segregation patterns among each mother and respective offspring. Captivity information, litter characteristics (comparison of the number of newborns, embryos and yolked ova) and molecular data altogether agreed with facultative parthenogenesis predictions in at least three out of the four mothers studied: B. atrox (ID#933) was heterozygous for three out of the four markers, and the sons S1 and S2 were homozygous; B. moojeni (BUT86) was heterozygous for two out of four markers, offspring S1, S3, E2, and E4, and O1 to O6 were homozygous; and B. leucurus (MJJS503) was heterozygous for three out of four markers, and son E1 and O1 were homozygous. B. moojeni (BUT44) was homozygous for all loci analyzed in the mother and offspring, which although not informative is also consistent with parthenogenesis. This study represents the first molecular confirmation of different pitviper species undergoing facultative parthenogenesis among Neotropical endemic snakes.

Keywords: Automixis; B. leucurus; B. moojeni; Genetic markers; Microsatellites; Neotropical snakes; Serpentes; Squamata.

Grants and funding

This work was supported by FAPESP (Jovem Pesquisador 2005/04557-3 and Auxílio Regular 2014/02885-2 for Maria José de J. Silva), INCTTOX (Proc. 573790/2008-6 and a Post-Doctoral CNPq Fellowship for José Salvatore Leister Patané #151069/2009-3), CNPq Grant #306490/2012-9, and CAPES (Finance Code 001) fellowship for Sergio D. Cubides-Cubillos, and Fundacão Butantan (payment of publication fee). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.