Embryonic development of a parthenogenetic vertebrate, the mourning gecko (Lepidodactylus lugubris)

Abstract

Background One goal of evolutionary developmental biology is to understand the role of development in the origin of phenotypic novelty and convergent evolution. Geckos are an ideal system to study this topic, as they are species‐rich and exhibit a suite of diverse morphologies—many of which have independently evolved multiple times within geckos. Results We characterized and discretized the embryonic development of Lepidodactylus lugubris—an all‐female, parthenogenetic gecko species. We also used soft‐tissue μCT to characterize the development of the brain and central nervous system, which is difficult to visualize using traditional microscopy techniques. Additionally, we sequenced and assembled a de novo transcriptome for a late‐stage embryo as a resource for generating future developmental tools. Herein, we describe the derived and conserved patterns of L. lugubris development in the context of squamate evolution and development. Conclusions This embryonic staging series, μCT data, and transcriptome together serve as critical enabling resources to study morphological evolution and development, the evolution and development of parthenogenesis, and other questions concerning vertebrate evolution and development in an emerging gecko model.

Do all geckos hatch in the same way? Histological and 3D studies of egg tooth morphogenesis in the geckos Eublepharis macularius Blyth 1854 and Lepidodactylus lugubris Duméril & Bibron 1836

“…Egg teeth of mourning geckos are distinct from other teeth and even from egg teeth of other squamate species in having a vessel; D, dentin; DL, dental lamina; DP, dental pulp; EO, enamel organ; ET, egg tooth; NC, nasal capsule; OB, odontoblasts; PMX, premaxilla; SR, stellate reticulum caudoventrally oriented cusps at their tip which might be connected with different hardness of their eggshell. Such specialized cusp has not been reported in recent staging series of L. lugubris (Griffing et al, 2019). It may be possible that the specimen analyzed in presented paper was closer to hatching as tips of the egg teeth were visible externally.…”

“…Such specialized cusp has not been reported in recent staging series of L . lugubris (Griffing et al, 2019). It may be possible that the specimen analyzed in presented paper was closer to hatching as tips of the egg teeth were visible externally.…”

Distinct patterns of pigment development underlie convergent hyperpigmentation between nocturnal and diurnal geckos (Squamata: Gekkota)

“…The overall spatial pattern of pigment accumulation exhibited by G. kuhli appears similar the other gecko species examinedpigment accumulates along the epidermis overlaying the developing brain and the dorsum, adjacent to the anterior portion of the neural tube. However, the early onset temporal pattern of pigment development exhibited by G. kuhli has not been described in any other gecko species to date [26,31,37,43,45,74,78,80,83], let alone other lizard species (e.g. [18,42,46,53]).…”

“…To briefly summarize, we removed embryos from eggs using #5 watchmaker's forceps while immersed in diethyl pyrocarbonate (DEPC) treated, RNase free 1% phosphatebuffered saline, and visualized and photographed using a Nikon SMZ 74ST stereoscope. As geckos exhibit interspecific variation between the precise time points (days post-oviposition; DPO) of developmental stages (Noro et al, 2009 [26, 37, 74, 80, 83];), we discretized and assigned developmental stages based on external morphology using previous embryonic staging series of geckos rather than characterizing by DPO [26,80].…”

Evo‐devo explores the endless forms most beautiful, from extreme traits to subtle diversities

“…They conduct a thorough and, it must be noted, incredibly beautiful analysis of the morphogenesis of this adhesive structure, including brightfield, SEM, SBF‐SEM, TEM, and immunofluorescence imaging. Finally, topping the charts of intriguing life‐history phenotypes, Griffing et al introduce a new squamate model for obligate parthenogenesis in the mourning gecko. They provide a detailed staging series, showing that hemipenis‐like structures persist in this all‐female species throughout embryonic development.…”