Mouse Development

From Embryology
Mouse.jpg

Introduction

Mouse E0-E5.jpg

The mouse (taxon-mus) has always been a good embryological model, generating easily (litters 8-20) and quickly (21d). Mouse embryology really expanded when molecular biologists used mice for gene knockouts. Suddenly it was necessary to understand development in order to understand the effect of knocking out the gene. There are over 450 different strains of inbred research mice, and these strains have recently been organized into a chart. While being an ideal model organism, only a relatively small amount (1.5%) of the total mouse genome has been sequenced. Those interested in the mouse reproductive cycle should also look at the mouse estrous cycle.

There are several systems for staging mouse development. The original and most widely used is the Theiler Stages system, which divides mouse development into 26 prenatal and 2 postnatal stages. [1]

mouse | original page

Early Mouse Development

Mouse E0-E5.jpg




Links: Mouse Stages

Later Mouse Development

Links: Mouse Stages | Mouse Timeline Detailed

Carnegie Stages Comparison

The table below gives an approximate comparison of human, mouse and rat embryos based upon Carnegie staging.

Species Stage
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Human [5] Days 20 22 24 28 30 33 36 40 42 44 48 52 54 55 58
Mouse [1] Days 9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15 15.5 16
Rat [6] Days 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15 15.5 16 16.5 17 17.5

Spermatozoa Development

Mouse spermatogonial self-renewal[7]

The process of spermatogenesis takes approximately 35 days:

  • mitotic phase (11 days)
  • meiotic phase (10 days)
  • post-meiotic phase (14 days)

Spermatogonial stem cells (SSCs)

The diploid germ cells, spermatogonial stem cells (SSCs), are located on the basement membrane of the seminiferous tubules

  • adult mouse testis about 30,000 SSCs
  • either divides into two new single cells
  • or into a pair of spermatogonia (Apr)
    • that do not complete cytokinesis and stay connected by an intercellular bridge

Primitive spermatogonia subset

  • Asingle (As, single isolated spermatogonia)
  • Apaired (Apr, interconnected spermatogonial pairs)
  • Aaligned (Aal, interconnected 4, 8, or 16 spermatogonia)
    • specifically termed Aal-4, Aal-8, and Aal-16

Primitive spermatogonia cells transform without cell division into more differentiating A1 spermatogonia that undergo 6 mitotic and 2 meiotic divisions to eventually form haploid spermatids.


Links: Spermatozoa Development | Testis Development

Neural Development

The data below is summarised from a study of early neural development in the mouse.[8]

  • initial fusion of apposing neural folds occurred at the level of the intermediate point between the third and fourth somites (caudal myelencephalon) both rostrally and caudally
  • second fusion - at the original rostral end of the neural plate (rostrodorsally).
  • third fusion - in the caudal diencephalon (rostrally and caudally)
    • followed by complete closure of the telencephalic neuropore at the midpoint of the telencephalic roof
    • then complete closure of the metencephalic neuropore at the rostral part of the metencephalic roof
  • fourth fusion - at the original caudal end of the neural plate (rostrally)
  • caudal neuropore completely closed at the level of the future 33rd somite

See also these 1980's papers.[9] [10]

Mouse Knockouts

Knowledge about mouse development has rapidly expanded as it has become the model animal system for genetic "knock out " studies. This technology actually requires development of defined breeding programs, pseudo-pregnancy, in vitro fertilization, molecular biology, and good old fashioned histology. Without understanding normal development the molecular biologists don't stand a hope of understanding what their gene knock out has done. There is a database of all existing mouse knockouts and their consequences.

Murine Development Control Genes

Kessel, M. and Gruss, P. Science 249 374-379 (1990)

An early review of the genes, and method of identifying them, involved in early mouse development. In particular discusses Homeobox genes. (homeobox is 183bp encoding a 61 amino acid DNA-binding domain)

  • Gene families
    • Hox
    • Pax
    • POU

The Genealogy Chart of Inbred Strains

This chart shows the origins and relationships of inbred mouse strains. The chart is available as a PDF document [../pdf/mouse_genealogy.pdf Locally] or from JAX Labs and was originally published by Beck etal., 2000.

Mouse Genome

Mouse Genome completed December 2002, a draft sequence and analysis of the genome of the C57BL/6J mouse strain.

  • less than 30,000 genes
  • estimated size is 2.5 Gb, smaller than the human genome
  • about 40% of the human and mouse genomes can be directly aligned
  • about 80% of human genes have one corresponding gene in the mouse genome
Links: Mouse Genome Sequencing: Mus musculus | Mouse Genome Informatics | Mouse Genome Project | Nature - Mouse Genome

References

  1. 1.0 1.1 The House Mouse: Atlas of Mouse Development by Theiler Springer-Verlag, NY (1972, 1989). | online book
  2. <pubmed>20704721</pubmed>| BMC Dev Biol.
  3. 3.0 3.1 3.2 3.3 3.4 <pubmed>16683035</pubmed>| PLoS Genetics
  4. <pubmed>18713865</pubmed>| PNAS
  5. <pubmed>400868</pubmed>
  6. Witschi, E. (1962) Development: Rat. In: Growth Including Reproduction and Morphological Development. Altman, P. L. , and D. S. Dittmer, ed. Fed. Am. Soc. Exp. Biol., Washington DC, pp. 304-314.
  7. Zhou Q, Griswold MD. Regulation of spermatogonia. StemBook [Internet]. Cambridge (MA): Harvard Stem Cell Institute. PMID20614596 | http://www.ncbi.nlm.nih.gov/books/NBK27035/ Bookshelf]
  8. Neurulation in the mouse: manner and timing of neural tube closure. Sakai Y. Anat Rec. 1989 Feb;223(2):194-203. PMID: 2712345
  9. The histogenetic potential of neural plate cells of early-somite-stage mouse embryos. Chan WY, Tam PP. J Embryol Exp Morphol. 1986 Jul;96:183-93. PMID: 3805982
  10. Neurulation in the mouse. I. The ontogenesis of neural segments and the determination of topographical regions in a central nervous system. Sakai Y. Anat Rec. 1987 Aug;218(4):450-7. PMID: 3662046

Search Pubmed

Search Pubmed: Mouse Development | Mouse Embryology

Additional Images

Movies

Fertilization 001 icon.jpg Parental genome mix 01 icon.jpg Nodal-cilia-001-icon.jpg Somitogenesis 01 icon.jpg
Fertilization
mouse
Parental genome
mouse
Nodal cilia rotation
mouse
Somitogenesis
mouse
Primordial germ cell 001 icon.jpg Primordial germ cell 002 icon.jpg Primordial germ cell 003 icon.jpg Mouse CT E11.5 movie-icon.jpg
Migration 1 Migration 2 Migration 3 microCT E11.5

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Cite this page: Hill, M.A. (2024, March 28) Embryology Mouse Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Mouse_Development

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