The influence of ploidy on the distribution of cells in chimaeric mouse blastocysts

Everett, Clare A.; West, John D.

doi:10.1017/s0967199400002896

Cited by 39 publications

(27 citation statements)

References 20 publications

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“…Similarly, in the nasal epithelia, only 2-14 scattered cells were found in all available sections of the five SeyNeu/Sey<--> + / + chimeras (10-32 sections per chimera). This is consistent with the low falsepositive frequencies seen in this [data not shownl and other [Everett and West 1996) studies. We conclude that SeyNe~/Sey cells are effectively excluded from the nasal epithelium as well as the lens.…”

Section: Cellular Composition Of Lens and Nasal Epitheliumsupporting

confidence: 93%

Multiple functions for Pax6 in mouse eye and nasal development.

Quinn¹,

West²,

Hill³

1996

Genes Dev.

223

156

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Mouse embryos, homozygous for the small eye (Sey) mutation die soon after birth with severe facial abnormalities that result from the failure of the eyes and nasal cavities to develop. Mutations in the Pax6 gene are responsible for the Sey phenotype. As a general disruption of eye and nasal development occurs in the homozygous Sey embryos, it is unclear, from the mutant phenotype alone, which tissues require functional Pax6. To examine the roles for Pax6 in eye and nasal development we produced chimeric mouse embryos composed of wild-type and Sey mutant cells. In these embryos we found that mutant cells were excluded from both the lens and nasal epithelium. Both of these tissues were smaller, and in some cases absent, in chimeras with high proportions of mutant cells. The morphology of the optic cup was also severely affected in these chimeras; mutant cells were excluded from the retinal pigmented epithelium and did not intermix with wild-type cells in other regions. The evidence shows that Pax6 has distinct roles in the nasal epithelium and the principal tissue components of the embryonic eye, acting directly and cell autonomously in the optic cup and lens. We suggest that Pax6 may promote cell surface changes in the optic cup and control the fate of the ectoderm from which the lens and nasal epithelia are derived.

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Section: Cellular Composition Of Lens and Nasal Epitheliumsupporting

confidence: 93%

Multiple functions for Pax6 in mouse eye and nasal development.

Quinn¹,

West²,

Hill³

1996

Genes Dev.

223

156

View full text Add to dashboard Cite

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“…Everett and West [12] and Everett et al [13] reported that 4n-cells made a greater contribution to the TE than to the ICM of E3.5 chimeras; in the present experiments, however, we did not find a high population of 4n-cells in the TE of E3.5 chimeras (data not shown), and chimeric embryos did not eliminate 4n-cells until E4.5. The results of the BrdU incorporation assay revealed that the capabilities of cell division and DNA synthesis of 4n cells were almost the same as those of 2n-cells until the 4-cell-compaction stage.…”

Section: Discussioncontrasting

confidence: 67%

“…Because of this characteristic of 4n-cells, tetraploid (4n) blastocysts are utilized as host embryos to produce embryonic stem cells that contribute effectively to the fetus [9][10][11]. Moreover, it has been reported that 4n↔2n-chimeric embryos display a restricted distribution of 4n-cells among the mural trophectoderm even at an embryonic age of 3.5 days (E3.5) [12,13], and the contribution of 4n-cells to 4n↔2n-embryos decreases from E3.5 to E4.5 [14].…”

mentioning

confidence: 99%

Tetraploid Cells of Enhanced Green Fluorescent Protein Transgenic Mice in Tetraploid/Diploid-Chimeric Embryos

Ishiguro

Kanô

Yamamoto

et al. 2005

Journal of Reproduction and Development

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Abstract. We succeeded in noninvasively analyzing the distribution of tetraploid (4n) cells in tetraploid↔diploid (4n↔2n) chimeric embryos by using enhanced green fluorescent protein (EGFP) transgenic (Tg) mouse embryos. We also evaluated whether this technique of analyzing 4n-cells in EGFP Tg 4n↔2n chimeric embryos could be used to determine which characteristics of 4n-cells cause the death of 4n-embryos and restricted distribution of 4n-cells in 4n↔2n-chimeric embryos after implantation. In our experiments, the distribution of 4n-cells in 4n↔2n-embryos was normal until an embryonic age of 3.5 days (E3.5). With respect to morphological development, there were no differences between 4n-, diploid (2n), 4n↔2n-, and diploid/diploid (2n↔2n) chimeric embryos, but the number of cells in the tetraploid (4n) blastocyst was smaller than expected. This decrease in the number of cells may have caused cell death or reduced the rate of cell division in 4n-cells, and may have restricted the distribution of 4n-cells in 4n↔2n-chimeric embryos. This study demonstrated the utility of EGFP transgenic mouse embryos for relatively easy and noninvasive study of the sequential distribution of cells in chimeric embryos. Key words: 4n↔2n-chimeric embryo, EGFP transgenic mouse, Implantation (J. Reprod. Dev. 51: [567][568][569][570][571][572] 2005) nhanced green fluorescent protein (EGFP) is a nontoxic marker that emits green fluorescence without exogenous substrates or cofactors, and it has been proven useful in numerous applications, such as in the selection of transgenic embryos [1]. Because the expression of EGFP can be easily observed by fluorescent microscopy, the use of EGFP transgenic (Tg) mouse embryos may be useful for analyzing the distribution of cells in chimeric embryos.Tetraploid (4n ) m ouse embryos with 80 chromosomes have been produced by either inhibition of cleavage or blastomere fusion [2][3][4][5]. These embryos develop into blastocysts in vitro, but with the exception of a report by Snow [6], they are general ly not cons idered to be capable of completing their full-term development [4,7]. On the other hand, in vivo tetraploid↔diploid (4n ↔ 2n )-chim eric embryos are capable of continuing to develop after implantation, and tetraploid (4n) cells in those embryos tend to distribute in derivatives of the trophectoderm and primitive endoderm lineages, but not in those of the primitive ectoderm [8].

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“…Additionally, the early cleavage divisions in human and mouse embryos have been shown to be error-prone and could contribute to the formation of mosaic embryos [19]. Studies also suggest that 2n/4n mosaicism is a normal feature of the later-stage embryos and that there is a nonrandom allocation of the tetraploid cells within the embryo [17,[20][21][22][23]. Ruangvutilert et al [17] described the presence of tetraploid cells in a significant proportion of arrested cleavage-stage human embryos (6/20) and at an even higher proportion of human blastocyst stage embryos (14/19).…”

Section: Discussionmentioning

confidence: 99%