Parthenogenesis in a captive Asian water dragon (Physignathus cocincinus) identified with novel microsatellites

Abstract

Reptiles show varying degrees of facultative parthenogenesis. Here we use genetic methods to determine that an isolated, captive female Asian water dragon produced at least nine offspring via parthenogenesis. We identified microsatellites for the species from shotgun genomic sequences, selected and optimized primer sets, and tested all of the offspring for a set of seven microsatellites that were heterozygous in the mother. We verified that the seven loci showed high levels of polymorphism in four wild Asian water dragons from Vietnam. In all cases, the offspring (unhatched, but developed eggs, or hatched young) had only a single allele at each locus, and contained only alleles present in the mother’s genotype (i.e., were homozygous or hemizygous). The probability that our findings resulted from the female mating with one or more males is extremely small, indicating that the offspring were derived from a single female gamete (either alone or via duplication and/or fusion) and implicating parthenogenesis. This is the first documented case of parthenogenesis in the Squamate family Agamidae.

Mixed‐sex offspring produced via cryptic parthenogenesis in a lizard

“…Nevertheless, such switching is considered rare in animals, particularly in vertebrates, as it is assumed that it is difficult to evolve and maintain the reproductive machineries necessary for both reproductive modes. With the advance of molecular genotyping, well‐documented cases of facultative parthenogenesis have become more frequent, particularly but not exclusively (Booth et al., 2012) in captive‐bred vertebrates, namely in sharks, snakes, monitor and agamid lizards and birds (Booth et al., 2014; Straube, Lampert, Geiger, Weiß, & Kirchhauser, 2016; Shibata, Sakata, Hirano, Nitasaka, & Sakabe, 2017; Miller et al., 2019). The fitness of individuals produced by facultative parthenogenesis is often low, and their development frequently ceases early in ontogeny, and in most cases, their fecundity has not yet been tested (for an exception, see Straube et al 2016).…”

Cross-Species BAC Mapping Highlights Conservation of Chromosome Synteny across Dragon Lizards (Squamata: Agamidae)

“…There are about 520 currently described agamid species [ 6 ] comprising six subfamilies that diverged around 70–120 million years ago [ 25 , 30 ]. Most agamid species are oviparous [ 6 ], and the groups includes species with obligate and facultative parthenogenesis [ 31 , 32 , 33 ]. Sex determination mode is relatively well studied in a few species from the subfamily Amphibolurinae [ 7 , 19 ], but not in the other five subfamilies ( Figure 1 ), highlighting a significant gap in our understanding of how sex chromosomes evolved in this widespread and chromosomally variable family.…”

The Role of Sperm Centrioles in Human Reproduction – The Known and the Unknown

“…However, it is important to note that mammalian parthenogenesis does not lead to viable offspring (Wininger, 2004). It has been proposed that imprinting defects are the main barrier to viability in mammalian parthenogenesis (Kono, 2006; Miller et al, 2019), but concomitant centriole abnormalities present during mammalian parthenogenesis may also contribute to this barrier.…”