Reproductive modes of the South American water snakes: A study system for the evolution of viviparity in squamate reptiles

Braz, Henrique B.; Scartozzoni, Rodrigo Roveri; Almeida‐Santos, Selma Maria

doi:10.1016/j.jcz.2016.04.003

Cited by 23 publications

(27 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…; Blackburn ; Braz et al. ). Reproductive patterns and the remarkable convergent evolution of viviparity has largely been studied in vertebrate species (for a review see Blackburn ), with a particular focus on the adaptive significance of extra‐vitelline embryo support, matrotrophy (Blackburn ; Crespi and Semeniuk ; Avise ).…”

mentioning

confidence: 99%

The genetics of egg retention and fertilization success inDrosophila: One step closer to understanding the transition from facultative to obligate viviparity

Hórvath

Kalinka

2018

Evolution

View full text Add to dashboard Cite

Oviparous, facultative egg retention enables Drosophila females to withhold fertilized eggs in their reproductive tracts until circumstances favor oviposition. The propensity to retain fertilized eggs varies greatly between species, and is correlated with other reproductive traits, such as egg size and ovariole number. While previous studies have described the phenomenon, no study to date has characterized within-species variation or the genetic basis of the trait. Here, we develop a novel microscope-based method for measuring egg retention in Drosophila females and determine the range of phenotypic variation in mated female egg retention in a subset of 91 Drosophila Genetic Reference Panel (DGRP) lines. We inferred the genetic basis of egg retention using a genome-wide association study (GWAS). Further, the scoring of more than 95,000 stained, staged eggs enabled estimates of fertilization success for each line. We found evidence that ovary- and spermathecae-related genes as well as genes affecting olfactory behavior, male mating behavior, male-female attraction and sperm motility may play a crucial role in post-mating physiology. Based on our findings we also propose potential evolutionary routes toward obligate viviparity. In particular, we propose that the loss of fecundity incurred by viviparity could be offset by benefits arising from enhanced mate discrimination, resource specialization, or modified egg morphology.

show abstract

mentioning

confidence: 99%

The genetics of egg retention and fertilization success inDrosophila: One step closer to understanding the transition from facultative to obligate viviparity

Hórvath

Kalinka

2018

Evolution

View full text Add to dashboard Cite

show abstract

“…As our comparative analyses included only seven terminal taxa, phylogeny is far from inclusive, and K ‐values for some traits were relatively high, some caution is advisable in interpreting the lack of statistical support for phylogenetic signal. Despite these caveats, we are confident to suggest the lack of phylogenetic signal in the traits evaluated because the viviparous lineages studied are likely unrelated (Braz et al., ). Moreover, conventional ANOVAs produced essentially the same results and trait values are clearly overdispersed across the phylogeny used here (Figures and ).…”

Section: Discussionmentioning

confidence: 86%

“…Both oviparous and viviparous Helicops have an eggshell around their eggs, but the eggshell structure differs between reproductive modes. Macroscopically, the eggshell is thick, opaque, and parchment‐like in oviparous Helicops , but it is thin and transparent in viviparous congeners (Braz et al., ). Histologically, the eggshell of oviparous Helicops exhibits the same three layers (a thin inner boundary, a thick shell membrane, and an outer amorphous layer) as the flexible‐shelled eggs of other oviparous squamates (Packard & DeMarco, ; Packard et al., ).…”

Section: Discussionmentioning

confidence: 99%

“…We studied the following five species of Helicops : two oviparous ( H. gomesi and H. hagmanni ), two viviparous ( H. carinicaudus and H. infrataeniatus ), and both oviparous and viviparous individuals of the reproductively bimodal H. angulatus (Braz et al., ). These species represent a fraction of the diversity of Helicops .…”

Section: Methodsmentioning

confidence: 99%

“…In addition, one species ( Helicops angulatus ) exhibits geographic variation in reproductive mode. This species is oviparous from northern to mid‐eastern and north‐eastern South America, but viviparous populations occur in north‐western to mid‐western South America (Braz et al., ). Importantly, viviparity has evolved independently at least three times in Helicops , thus providing replication for both comparisons of closely related taxa varying in reproductive mode and reconstructions of the morphological modifications associated with the evolution of viviparity (Braz et al., ).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Uterine and eggshell modifications associated with the evolution of viviparity in South American water snakes (Helicopsspp.)

et al. 2018

Self Cite

View full text Add to dashboard Cite

The evolution of viviparity requires eggshell thinning to bring together the maternal uterus and extraembryonic membranes to form placentae for physiological exchanges. Eggshell thinning likely involves reduced activity of the uterine glands that secrete it. We tested these hypotheses by comparing the uterine and eggshell structure and histochemistry among oviparous and viviparous water snakes (Helicops) using phylogenetic methods. Eggshell thinning occurred convergently in all three origins of viviparity in Helicops and was accomplished by the loss of the mineral layer and thinning of the shell membrane. Uterine glands secrete the shell membrane in both oviparous and viviparous Helicops. These glands increase during vitellogenesis regardless of the reproductive mode, but they always reach smaller sizes in viviparous forms. As there is no phylogenetic signal in eggshell thickness and gland dimensions, we conclude that interspecific differences are related to reproductive mode and not phylogeny. Therefore, our results support the hypothesis that eggshell thinning is associated with the evolution of viviparity and that such thinning result from a reduction in gland size in viviparous taxa. Interestingly, the shell membrane thickness of viviparous females of the reproductively bimodal Helicops angulatus is intermediate between their oviparous and viviparous congeners. Thus, although eggshell thinning is required by the evolution of viviparity, a nearly complete loss of this structure is not. However, uterine gland dimensions are similar across viviparous Helicops. Fewer glands or their functional repurposing may explain the thinner shell membrane in viviparous species of Helicops in comparison to viviparous females of the bimodal H. angulatus.

show abstract

Evolution of viviparity

Whittington,

Pathirana,

Hodgson

2024

Hormones and Reproduction of Vertebrates

View full text Add to dashboard Cite

Reproductive modes of the South American water snakes: A study system for the evolution of viviparity in squamate reptiles

Cited by 23 publications

References 46 publications

The genetics of egg retention and fertilization success inDrosophila: One step closer to understanding the transition from facultative to obligate viviparity

The genetics of egg retention and fertilization success inDrosophila: One step closer to understanding the transition from facultative to obligate viviparity

Uterine and eggshell modifications associated with the evolution of viviparity in South American water snakes (Helicopsspp.)

Evolution of viviparity

Contact Info

Product

Resources

About