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Despite the importance of maternally selected nests in shaping offspring phenotypes, our understanding of how the nest environment affects embryonic development and offspring traits of most non-avian reptiles is rather limited largely due to the logistical difficulty in locating their nests. To identify the relative contributions of environmental (temporal [seasonal] and spatial [nest-site]) and intrinsic (clutch) factors on embryonic development and offspring traits, we conducted a cross-fostering experiment by swapping eggs between maternally-selected nests of the toad-headed agama (Phrynocephalus przewalskii) in the field. We found that nest environment explained a large proportion of variation in incubation duration, hatching success, and offspring size and growth. In contrast, clutch only explained a small proportion of variation in these embryonic and offspring traits. More significantly, compared with spatial effects, seasonal effects explained more phenotypic variation in both embryonic development and offspring traits. Eggs laid early in the nesting season had longer incubation durations and produced smaller hatchlings with higher post-hatching growth rates than did later-laid eggs. Consequently, hatchlings from early-laid eggs reached larger body sizes prior to winter. In addition, we found that female toad-headed agama did not select nests specific to reaction norms of their own offspring because hatchlings from original or translocated nests had similar phenotypic traits. Overall, our study demonstrates the importance of seasonal variation in nest environments in determining embryonic development and offspring phenotypes, which has not been widely appreciated at least in non-avian reptiles., (© 2020 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.)

We sequenced the complete mitochondrial genome of Gekko chinensis, which is an endemic species to China. The complete mitogenome is 17,906 bp in size, containing 37 genes coding for 13 proteins, two ribosomal RNAs, 22 transfer RNAs, and a control region. The A + T content of the overall base composition of H-strand is 61.1% (T: 27.6%, C: 25.5%, A: 33.5%, and G: 13.4%). The major non-coding region (control region) is 2530 bp in length and the A + T content is 67.9%. Besides, four tandem repeats were found within the control region. In Bayesian inference (BI), maximum likelihood (ML) and maximum parsimony (MP) trees, we found G. chinensis is a sister clade to Gekko swinhonis.

Simple Summary: Global climate change is a growing threat to the lives and ranges of reptile species. The present study examines three lizard species (Calotes versicolor, Ateuchosaurus chinensis, and Hemidactylus bowringii) that share a sympatric distribution in the Guangzhou region of Guangdong, China. Mitochondria act as energy-producing centers, and the present study analyses the effects of low temperatures in the context of warm winters on lizards, by examining their responses to low-temperature stress at the level of mitochondrial gene expression. This present study analyses the effects of low temperatures in the context of warm winters on the mitochondrial gene expression of lizards and reveals the implications of the distribution within it. Ecological factors related to climate extremes have a significant influence on the adaptability of organisms, especially for ectotherms such as reptiles that are sensitive to temperature change. Climate extremes can seriously affect the survival and internal physiology of lizards, sometimes even resulting in the loss of local populations or even complete extinction. Indeed, studies have shown that the expression levels of the nuclear genes and mitochondrial genomes of reptiles change under low-temperature stress. At present, the temperature adaptability of reptiles has rarely been studied at the mitochondrial genome level. In the present study, the mitochondrial genomes of three species of lizards, Calotes versicolor, Ateuchosaurus chinensis, and Hemidactylus bowringii, which live in regions of sympatry, were sequenced. We used RT-qPCR to explore the level of mitochondrial gene expression under low-temperature stress, as compared to a control temperature. Among the 13 protein-coding genes (PCGs), the steady-state transcript levels of ND4L, ND1, ATP6, and COII were reduced to levels of 0.61 ± 0.06, 0.50 ± 0.08, 0.44 ± 0.16, and 0.41 ± 0.09 in C. versicolor, respectively, compared with controls. The transcript levels of the ND3 and ND6 genes fell to levels of just 0.72 ± 0.05 and 0.67 ± 0.05 in H. bowringii, compared with controls. However, the transcript levels of ND3, ND5, ND6, ATP6, ATP8, Cytb, and COIII genes increased to 1.97 ± 0.15, 2.94 ± 0.43, 1.66 ± 0.07, 1.59 ± 0.17, 1.46 ± 0.04, 1.70 ± 0.16, and 1.83 ± 0.07 in A. chinensis. Therefore, the differences in mitochondrial gene expression may be internally related to the adaptative strategy of the three species under low-temperature stress, indicating that low-temperature environments have a greater impact on A. chinensis, with a small distribution area. In extreme environments, the regulatory trend of mitochondrial gene expression in reptiles is associated with their ability to adapt to extreme climates, which means differential mitochondrial genome expression can be used to explore the response of different lizards in the same region to low temperatures. Our experiment aims to provide one new research method to evaluate the potential extinction of reptile species in warm winter climates. [ABSTRACT FROM AUTHOR]