Talk:Animal Development

Axolotl

Axolotl Development - (Ambystoma mexicanum) A salamander where the larvae do not undergo metamorphosis and adults remain gilled and aquatic. The ability to regenrate limbs has been used to study developmental pattern formation and nerve regeneration. Also used to investigate neural crest migration.

Elephant

Elephant and calf .

Obstetrics in elephants

Theriogenology. 2008 Jul 15;70(2):131-44. Epub 2008 May 21

Hermes R, Saragusty J, Schaftenaar W, Göritz F, Schmitt DL, Hildebrandt TB.

Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany. hermes@izw-berlin.de Abstract Obstetrics, one of the oldest fields in veterinary medicine, is well described and practiced in domestic and exotic animals. However, when providing care during elephant birth or dystocia, veterinary intervention options differ greatly from any domestic species, and are far more limited due to the dimensions and specific anatomy of the elephant reproductive tract. In addition, aging of captive elephant populations and advanced age of primiparous females make active birth management increasingly important. Intrauterine infection, uterine inertia and urogenital tract pathologies are emerging as major causes for dystocia, often leading to foetal and dam death. This paper reviews the current knowledge on elephant birth and the factors associated with dystocia. It then summarises recommendations for birth and dystocia management. As Caesarean section, the most common ultima ratio in domestic animal obstetrics, is lethal and therefore not an option in the elephant, non-invasive medical treatment, induction of the Fergusson reflex or the conscious decision to leave a retained foetus until it is expelled voluntarily, are key elements in elephant obstetrics. Surgical strategies such as episiotomy and foetotomy are sometimes inevitable in order to try to save the life of the dam, however, these interventions result in chronic post-surgical complications or even fatal outcome. Limited reliable data on serum calcium concentrations, and pharmacokinetics and effect of exogenous oestrogen, oxytocin, and prostaglandins during birth provide the scope of future research, necessary to advance scientific knowledge on obstetrics in elephants.

PMID: 18499243

http://www.ncbi.nlm.nih.gov/pubmed/18499243

Foetal age determination and development in elephants

Hildebrandt T, Drews B, Gaeth AP, Goeritz F, Hermes R, Schmitt D, Gray C, Rich P, Streich WJ, Short RV, Renfree MB. Proc Biol Sci. 2007 Feb 7;274(1608):323-31.

Elephants have the longest pregnancy of all mammals, with an average gestation of around 660 days, so their embryonic and foetal development have always been of special interest. Hitherto, it has only been possible to estimate foetal ages from theoretical calculations based on foetal mass. The recent development of sophisticated ultrasound procedures for elephants has now made it possible to monitor the growth and development of foetuses of known gestational age conceived in captivity from natural matings or artificial insemination. We have studied the early stages of pregnancy in 10 captive Asian and 9 African elephants by transrectal ultrasound. Measurements of foetal crown-rump lengths have provided the first accurate growth curves, which differ significantly from the previous theoretical estimates based on the cube root of foetal mass. We have used these to age 22 African elephant foetuses collected during culling operations. Pregnancy can be first recognized ultrasonographically by day 50, the presumptive yolk sac by about day 75 and the zonary placenta by about day 85. The trunk is first recognizable by days 85-90 and is distinct by day 104, while the first heartbeats are evident from around day 80. By combining ultrasonography and morphology, we have been able to produce the first reliable criteria for estimating gestational age and ontological development of Asian and African elephant foetuses during the first third of gestation.

PMID: 17164195

Grasshopper Development

Grasshopper Development - A species used in neural development studies.

Killifish

Embryonic development of the self-fertilizing mangrove killifish Kryptolebias marmoratus

Dev Dyn. 2011 Jul;240(7):1694-704. doi: 10.1002/dvdy.22668.

Mourabit S, Edenbrow M, Croft DP, Kudoh T. Source Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom. Abstract The mangrove killifish, Kryptolebias marmoratus, is a self-fertilizing vertebrate offering vast potential as a model species in many biological disciplines. Previous studies have defined developmental stages but lacked visual representations of the various embryonic structures. We offer detailed photographic images of K. marmoratus development with revised descriptions. An improved dechorionation method was developed to provide high resolution photographs, in addition to a microinjection technique enabling cell marking in the yolk syncytial layer. Embryos were also treated with PTU (1-phenyl 2-thiourea), an inhibitor of melanogenesis, to provide optical transparency revealing internal structures in late stages of development. Chemical exposures (PTU and retinoic acid) demonstrated that K. marmoratus embryos were sensitive to chemicals, illustrating further their usefulness in developmental biology studies. Our data suggest that K. marmoratus embryos are easily used and manipulated, supporting the use of this hermaphroditic vertebrate as a strong comparative model system in embryology, evolution, genetics, environmental and medical biology.

Copyright © 2011 Wiley-Liss, Inc.

PMID 21674684

Koala

Koala Development

Lizard

An embryonic staging table for in ovo development of Eublepharis macularius, the leopard gecko. Wise PA, Vickaryous MK, Russell AP. Anat Rec (Hoboken). 2009 Aug;292(8):1198-212. PMID: 19645023

http://onlinelibrary.wiley.com/doi/10.1002/ar.20945/full

Monkey

Monkey Development - a model used for primate development studies.

Salmon Development

Salmon Development

Sea Urchin Development

Sea Urchin Development - A species used to study very early development from fertilization onward.