A direct technique for the preparation of chromosomes from early equine embryos

Romagnano, A.; Wa, King; Cl, Richer; Ma, Peifeng

doi:10.1139/g85-054

Cited by 17 publications

(8 citation statements)

References 5 publications

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“…Fixation on slides was performed as previously described for Day-2 to Day-7 embryos by King et al (1979) and for Day-14 embryos by Romagnano et al (1985). These slides were then lightly stained with Giemsa and examined.…”

Section: Methodsmentioning

confidence: 99%

Nucleolus organizer regions and nucleoli in preattachment bovine embryos

King¹,

Niar²,

Chartrain³

et al. 1988

Reproduction

127

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Embryos (1-cell to elongated blastocyst stage) were recovered from superovulated heifers at surgery (Days 2-4; oestrus = Day 0), after slaughter (Day 4), or by transcervical flushing (Days 6, 7 and 14). The 175 embryos were cultured for 4, 8, 24 or 48 h, fixed on slides and sequentially stained with Giemsa and silver nitrate. Twenty-three 2-cell to blastocyst-stage embryos were fixed, embedded and examined by transmission electron microscopy. Argentophilic nucleolus organizer regions (Ag-NORs), indicative of transcriptionally active rRNA genes, were observed in embryos in which short- or long-term culture began at or after the late 8-cell stage. The nucleoli of embryonic cells also showed increased affinity for silver from the 8-cell stage onward. Differences in the number of Ag-NORs observed after the 8-cell stage reached statistical significance only when Day-5 and Day-7 embryos cultured for 4 h were compared. Ultrastructurally, the nucleoli were seen to develop from small, dense, fibrillar masses at the 2-cell stage, to ring-shaped structures (signifying a low level of activity) at the 8-cell stage. At the 16-cell stage the nucleoli became reticulated, suggesting an increase in activity, and by the morula and blastocyst stages they were characteristic of fully active nucleoli. It is concluded that a significant transcriptional activity of the rRNA genes in the embryos of cattle begins around the 8-cell stage.

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Section: Methodsmentioning

confidence: 99%

Nucleolus organizer regions and nucleoli in preattachment bovine embryos

King¹,

Niar²,

Chartrain³

et al. 1988

Reproduction

127

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“…kg -1 ZEN respectively, while the third group received only propylene glycol. In all groups, 5 females were killed at day 13 of pregnancy, the chromosomes preparations were obtained from the produced whole embryos using the methodology described by Romagnano et al [25]. The other 5 females in each group were killed at day 17 of pregnancy and the embryos were morphologically examined, counted, weighed and the number of resorption sites for live and dead fetuses was recorded.…”

Section: Effect On Embryo Somatic Chromosomesmentioning

confidence: 99%

Genotoxic evaluation for the estrogenic mycotoxin zearalenone

Makawy¹,

Hassanane²,

Alla

2001

Reprod. Nutr. Dev.

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“…Chromosome preparations were made from day-14 embryos and from the new-born calves by the methods described by Romagnano et al (1985) and Hageltorn (19801, respectively.…”

Section: Chromosome Marker Andmentioning

confidence: 99%

Production of chimaeric bovine embryos and calves by aggregation of inner cell masses with morulae

Picard

Chartrain

King

et al. 1990

Molecular Reproduction Devel

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Bovine inner cell masses (ICMs) were isolated by immunosurgery at day 8 or 10, or by dissection at day 14, and combined with day-5.5 morulae. Aggregation was obtained between 89%, 62%, and 0% of the day-5:day-8, day-5:day-10, day-5:day-14 composites, respectively. Chromosome analysis of composites, respectively. Chromosome analysis of composites potentially carrying the 1/29 translocation as a chromosome marker and temporarily transferred to the bovine uterus for 8 days showed that chimaeric day-14 embryos can be obtained from day-5:day-8 aggregation. The definitive transfer of eight day-5:day-8 and 11 day-5:day-10 composites resulted in the birth of six and four calves, respectively; five of the six, but none of the four, were chimaeric. The five chimaeras showed mostly the ICM phenotype. The morphological differences between ICMs at different stages of development were examined by electron microscopy and related to the success of the aggregation technique. It is concluded that bovine embryonic cells can regulate for at least 3 days difference in development but not 5 days even though aggregation is still possible.

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A direct technique for the preparation of chromosomes from early equine embryos

Cited by 17 publications

References 5 publications

Nucleolus organizer regions and nucleoli in preattachment bovine embryos

Nucleolus organizer regions and nucleoli in preattachment bovine embryos

Genotoxic evaluation for the estrogenic mycotoxin zearalenone

Production of chimaeric bovine embryos and calves by aggregation of inner cell masses with morulae

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