Sheep Development
Introduction
Domestic sheep (Ovis aries)
- term gestational days = 145 days
Some Recent Findings
|
Development Overview
- day 4 - embryo enters the uterus at the morula stage of development
- day 6 - develops into a blastocyst
- day 8 - blastocyst hatches from zona pellucida
- day 11-16 - elongates to a filamentous form
- day 14 - 16 - binucleate cells begin to differentiate in the trophoblast
- day 16 - adplantation
See also Implantation mechanisms: insights from the sheep[4]
Dolly
A female domestic sheep remarkable in being the first mammal to be cloned from an adult somatic cell, using the process of nuclear transfer.[5]
Cloned by Ian Wilmut, Keith Campbell and colleagues at the Roslin Institute near Edinburgh in Scotland, born on 5 July 1996 and she lived until the age of six (5 July 1996 – 14 February 2003). The cell used as the donor for the cloning of Dolly was taken from a mammary gland, and the production of a healthy clone therefore proved that a cell taken from a specific part of the body could recreate a whole individual. As Dolly was cloned from part of a mammary gland, she was named after the famously curvaceous country western singer Dolly Parton.
Oocyte Development
Sheep Oocyte Distribution of Telomerase reverse transcriptase
The following oocyte images are from a recent study of sheep in vitro follicle development.[6]
preantral | early antral |
early antral | preovulatory follicle |
- TERT - Red (Cy3-conjugated secondary antibody) (telomerase reverse transcriptase, TERT)
- DNA - Green (SYBR Green 14/I)
- Sheep Oocyte TERT: preantral | early antral | early antral | preovulatory follicle | Oocyte Development | Sheep Development
Respiratory
Phases of fetal lung development:[7]
- embryonic - 0 to 40 days.
- pseudoglandular - 40 to 80 days.
- canalicular - 80 to 120 days.
- saccular - 120 to term 148 days gestation.
- Links: Respiratory Development
Immune
Lymphocytes development has been characterised by an immunohistology study of T lymphocytes in the sheep fetal spleen.[8]
- 43-44 days of gestation, SBU-T1- and SBU-T8-positive lymphocytes were present in low numbers.
- 45-50 days of gestation Surface immunoglobulin (sIg) was first detected on fetal spleen cells
- 50-55 days of gestation SBU-T4, 20.96-, 25.69-, 38.38-, or 46.66-positive lymphocytes present.
- 57 days of gestation SBU-T19 lymphocytes appeared.
- Links: Immune Development
References
Reviews
<pubmed>19726075</pubmed> <pubmed>16008756</pubmed>
Articles
<pubmed>19909921</pubmed> <pubmed>15047940</pubmed>| Reproduction
Search PubMed
Search Pubmed: sheep development | ovine development | ovine embryo development
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Cite this page: Hill, M.A. (2024, June 19) Embryology Sheep Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Sheep_Development
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G