Nucleolus organizer regions and nucleoli in preattachment bovine embryos

Occurrence of multiple nucleolus organizer regions and intraspecific karyotype variation in Scaptotrigona xanthotricha Moure (Hymenoptera, Meliponini).

Scaptotrigona xanthotricha has a wide geographic distribution in the Brazilian Atlantic rainforest. One population from southeast and two from northeast Brazil were analyzed and were found to have chromosome polymorphisms. Although the chromosome number 2n = 34 is conserved in this species, karyotypic analysis revealed clear differences between the three populations. Congruent and ubiquitous mu...

Ribosomal Rna in the Nucleolus Organizer

Nucleolar organizer regions, satellite associations and nucleoli of goat cells (Capra hircus)

The Polish White Improved goat karyotype consists of 29 pairs of acrocentric autosomes, a large acrocentric X chromosome and a metacentric Y chromosome which is the smallest in the karyotype. Staining of chromosomes with AgNO3 solution has revealed active nucleolar organizer regions (NOR) in terminal parts of q arms of pair 2, 3, 4, 5, and 28 chromosomes. Out of the total of 100 analysed cells ...

Gene expression and protein distribution of leptin and its receptor in bovine oocytes and preattachment embryos produced in vitro.

Many investigations point out the important role of leptin during the preimplantation development. Transcripts for the leptin gene (LEP) and its receptor (LEPR) have been identified in several tissues related to reproduction (e.g. ovaries, testis and oviduct) in both human and mouse. This work shows for the first time the expression and distribution patterns of LEP and LEPR in bovine oocytes an...

Update on the Nucleolus Nucleoli: Composition, Function, and Dynamics

The nucleus is a highly organized structure. However, unlike cytoplasmic organelles, nuclear substructures are not bounded by membranes, but rather are held together by interactions between their component proteins and nucleic acids, and are thus probably best regarded as giant, extended multimolecular complexes. The nucleolus is themost prominent of these structures. It is the site of transcri...