Lizard Development

From Embryology
Revision as of 10:53, 16 July 2012 by Z8600021 (Talk | contribs)

Jump to: navigation, search

Introduction

Anolis carolinensis (green anole) mating.
Australian water skink embryo

Lizards and snakes represent scaled reptiles (squamata). Lizard development involves an amniotic egg, that evolutionary (~320 million years ago) freed the vertebrates from their aquatic (water) to a terrestrial (land) environment. The Galápagos Islands marine iguana was also made famous by Charles Darwin's historic evolution studies.

The genome of the lizard Anolis carolinensis (green anole) from southeastern United States has a karyotype of 18 chromosomes, comprising six pairs of large macrochromosomes and 12 pairs of small microchromosomes, and has recently been sequenced [1]. Interestingly, almost all reptilian genomes also contain "microchromosomes", very small chromosomes less than 20 Mb in sequence size. (More? Genome)

Some Recent Findings

  • Patterns of interspecific variation in the heart rates of embryonic reptiles[2] "New non-invasive technologies allow direct measurement of heart rates (and thus, developmental rates) of embryos. We applied these methods to a diverse array of oviparous reptiles (24 species of lizards, 18 snakes, 11 turtles, 1 crocodilian), to identify general influences on cardiac rates during embryogenesis. Heart rates increased with ambient temperature in all lineages, but (at the same temperature) were faster in lizards and turtles than in snakes and crocodilians. We analysed these data within a phylogenetic framework. Embryonic heart rates were faster in species with smaller adult sizes, smaller egg sizes, and shorter incubation periods. Phylogenetic changes in heart rates were negatively correlated with concurrent changes in adult body mass and residual incubation period among the lizards, snakes (especially within pythons) and crocodilians. The total number of embryonic heart beats between oviposition and hatching was lower in squamates than in turtles or the crocodilian. Within squamates, embryonic iguanians and gekkonids required more heartbeats to complete development than did embryos of the other squamate families that we tested. These differences plausibly reflect phylogenetic divergence in the proportion of embryogenesis completed before versus after laying."
  • Reptilian spermatogenesis: A histological and ultrastructural perspective[3] "Until recently, the histology and ultrastructural events of spermatogenesis in reptiles were relatively unknown. Most of the available morphological information focuses on specific stages of spermatogenesis, spermiogenesis, and/or of the mature spermatozoa. No study to date has provided complete ultrastructural information on the early events of spermatogenesis, proliferation and meiosis in class Reptilia. Furthermore, no comprehensive data set exists that describes the ultrastructure of the entire ontogenic progression of germ cells through the phases of reptilian spermatogenesis (mitosis, meiosis and spermiogenesis). The purpose of this review is to provide an ultrastructural and histological atlas of spermatogenesis in reptiles. The morphological details provided here are the first of their kind and can hopefully provide histological information on spermatogenesis that can be compared to that already known for anamniotes (fish and amphibians), birds and mammals. The data supplied in this review will provide a basic model that can be utilized for the study of sperm development in other reptiles. The use of such an atlas will hopefully stimulate more interest in collecting histological and ultrastructural data sets on spermatogenesis that may play important roles in future nontraditional phylogenetic analyses and histopathological studies in reptiles."

Taxon

Iguana - historic drawing

root; cellular organisms; Eukaryota; Opisthokonta; Metazoa; Eumetazoa; Bilateria; Coelomata; Deuterostomia; Chordata; Craniata; Vertebrata; Gnathostomata; Teleostomi; Euteleostomi; Sarcopterygii; Tetrapoda; Amniota; Sauropsida; Sauria; Lepidosauria

Squamata (squamates) - snakes and lizards.

  • Iguania (iguanian lizards) - arboreal with primitively fleshy, non-prehensile tongues, highly modified in the chameleons.
    • Acrodonta
    • Iguanidae (iguanid lizards)
  • Scleroglossa
    • Amphisbaenia
    • Anguimorpha (anguimorph lizards)
    • Gekkota - all geckos and the limbless Pygopodidae.
    • Scincomorpha (scincomorph lizards)
    • Serpentes (snakes)
  • unclassified Squamata
Links: Taxonomy Browser Lizards

Development Overview

Australian Water Skink

Genome

Anolis carolinensis (green anole) mating.

Anolis carolinensis (green anole)

The genome of the lizard Anolis carolinensis (green anole) from southeastern United States has a karyotype of 18 chromosomes, comprising six pairs of large macrochromosomes and 12 pairs of small microchromosomes, and has recently been sequenced [1]. Interestingly, almost all reptilian genomes also contain "microchromosomes", very small chromosomes less than 20 Mb in sequence size.

It is a model organism for laboratory-based studies of organismal function and for field studies of ecology and evolution. This species was chosen for genome sequencing in part because of the ease and low expense of captive breeding, well studied brain, and sophisticated color vision. It is also well suited for studies involving the role of hormones in development and adult nervous system plasticity. (modified from Genome)

Search PubMed Genome: Lizard

Historic

Fig. 343. Head of a Lizard Embryo (Sphenodon punctatum Hatteria)

Schwalbe (1891) points out the significant fact that in reptiles that lack an external ear (lizard and turtle) there occur distinct hillocks in the embryo, resembling those in vertebrates that develop an auricle. These hillocks undergo degeneration and are reduced to the level of the surrounding skin. He finds in both birds and reptiles hillocks corresponding to the tragus and antitragus hillocks of His. These animals have one hillock (Auricularkegel), situated dorsal to the first cleft, which seems to represent a more primitive apparatus than is present in mammals, although it may be related to the helix system. In Salachians it possesses a spiracle.

(From Contributions to Embryology No.69)

References

  1. 1.0 1.1 Jessica Alföldi, Federica Di Palma, Manfred Grabherr, Christina Williams, Lesheng Kong, Evan Mauceli, Pamela Russell, Craig B Lowe, Richard E Glor, Jacob D Jaffe, David A Ray, Stephane Boissinot, Andrew M Shedlock, Christopher Botka, Todd A Castoe, John K Colbourne, Matthew K Fujita, Ricardo Godinez Moreno, Boudewijn F ten Hallers, David Haussler, Andreas Heger, David Heiman, Daniel E Janes, Jeremy Johnson, Pieter J de Jong, Maxim Y Koriabine, Marcia Lara, Peter A Novick, Chris L Organ, Sally E Peach, Steven Poe, David D Pollock, Kevin de Queiroz, Thomas Sanger, Steve Searle, Jeremy D Smith, Zachary Smith, Ross Swofford, Jason Turner-Maier, Juli Wade, Sarah Young, Amonida Zadissa, Scott V Edwards, Travis C Glenn, Christopher J Schneider, Jonathan B Losos, Eric S Lander, Matthew Breen, Chris P Ponting, Kerstin Lindblad-Toh The genome of the green anole lizard and a comparative analysis with birds and mammals. Nature: 2011, 477(7366);587-91 PMID: 21881562
  2. Wei-Guo Du, Hua Ye, Bo Zhao, Ligia Pizzatto, Xiang Ji, Richard Shine Patterns of interspecific variation in the heart rates of embryonic reptiles. PLoS ONE: 2011, 6(12);e29027 PMID: 22174948 | PMC3184186
  3. Kevin M Gribbins Reptilian spermatogenesis: A histological and ultrastructural perspective. Spermatogenesis: 2011, 1(3);250-269 PMID: 22319673

Reviews

Bridget F Murphy, Michael B Thompson A review of the evolution of viviparity in squamate reptiles: the past, present and future role of molecular biology and genomics. J. Comp. Physiol. B, Biochem. Syst. Environ. Physiol.: 2011, 181(5);575-94 PMID: 21573966

Edward M Dzialowski, Tushar Sirsat, Saskia van der Sterren, Eduardo Villamor Prenatal cardiovascular shunts in amniotic vertebrates. Respir Physiol Neurobiol: 2011, 178(1);66-74 PMID: 21513818

T Gamble A review of sex determining mechanisms in geckos (Gekkota: Squamata). Sex Dev: 2010, 4(1-2);88-103 PMID: 20234154


Articles

Patrick A D Wise, Matthew K Vickaryous, Anthony P Russell An embryonic staging table for in ovo development of Eublepharis macularius, the leopard gecko. Anat Rec (Hoboken): 2009, 292(8);1198-212 PMID: 19645023

Miyuki Noro, Asaka Uejima, Gembu Abe, Makoto Manabe, Koji Tamura Normal developmental stages of the Madagascar ground gecko Paroedura pictus with special reference to limb morphogenesis. Dev. Dyn.: 2009, 238(1);100-9 PMID: 19097047

Melissa A Storm, Michael J Angilletta Rapid assimilation of yolk enhances growth and development of lizard embryos from a cold environment. J. Exp. Biol.: 2007, 210(Pt 19);3415-21 PMID: 17872995 | J Exp Biol. Marissa Fabrezi, Virginia Abdala, María Inés Martínez Oliver Developmental basis of limb homology in lizards. Anat Rec (Hoboken): 2007, 290(7);900-12 PMID: 17415759

Thomas J Sanger, Jeremy J Gibson-Brown The developmental bases of limb reduction and body elongation in squamates. Evolution: 2004, 58(9);2103-6; discussion 2107-8 PMID: 15521466

V Muthukkaruppan, P Kanakambika, V Manickavel, K Veeraraghavan Analysis of the development of the lizard, Calotes versicolor. I. A series of normal stages in the embryonic development. J. Morphol.: 1970, 130(4);479-89 PMID: 5437480

M B Mohammed Development of the lizard limb as shown by the distribution of [35S]sulphate incorporation. J. Anat.: 1984, 138 ( Pt 3);399-403 PMID: 6429113


Books

Search PubMed

Search PubMed: Lizard development | Anolis carolinensis

External Links

External Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name.


Glossary Links

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols

Cite this page: Hill, M.A. (2015) Embryology Lizard Development. Retrieved August 4, 2015, from https://embryology.med.unsw.edu.au/embryology/index.php/Lizard_Development

What Links Here?
© Dr Mark Hill 2015, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G