Difference between revisions of "Lizard Development"

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'''Anolis carolinensis''' (green anole) The green anole is a lizard of the southeastern United States.
 
'''Anolis carolinensis''' (green anole) The green anole is a lizard of the southeastern United States.
  
The green or common anole Anolis carolinensis is an arboreal lizard found in the southeastern United States and Caribbean. 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. (From [http://www.ncbi.nlm.nih.gov/genome/708 Genome]  
+
The green or common anole Anolis carolinensis is an arboreal lizard found in the southeastern United States and Caribbean. 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<ref><pubmed>21881562</pubmed></ref> 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 [http://www.ncbi.nlm.nih.gov/genome/708 Genome]  
  
  

Revision as of 06:53, 24 June 2012

Introduction

Australian water skink embryo

Lizards and snakes represent scaled reptiles (squamata).

Some Recent Findings

  • Patterns of interspecific variation in the heart rates of embryonic reptiles[1] "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[2] "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

Genome

Anolis carolinensis (green anole) The green anole is a lizard of the southeastern United States.

The green or common anole Anolis carolinensis is an arboreal lizard found in the southeastern United States and Caribbean. 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[3] 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. <pubmed>22174948</pubmed>
  2. <pubmed>22319673</pubmed>
  3. <pubmed>21881562</pubmed>

Reviews

<pubmed></pubmed>


Articles

<pubmed>19645023</pubmed> <pubmed>19097047</pubmed> <pubmed>17415759</pubmed> <pubmed>15521466</pubmed> <pubmed>5437480</pubmed> <pubmed>6429113</pubmed>

Books

Search PubMed

Search PubMed: Lizard development

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. Links to any external commercial sites are provided for information purposes only and should never be considered an endorsement. UNSW Embryology is provided as an educational resource with no clinical information or commercial affiliation.


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Cite this page: Hill, M.A. (2021, July 25) Embryology Lizard Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Lizard_Development

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© Dr Mark Hill 2021, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G