TY - JOUR

T1 - On some structural and evolutionary aspects of rDNA amplification in oogenesis of Trachemys scripta turtles

AU - Davidian, Asya

AU - Koshel, Elena

AU - Dyomin, Alexander

AU - Galkina, Svetlana

AU - Saifitdinova, Alsu

AU - Gaginskaya, Elena

N1 - Davidian, A., Koshel, E., Dyomin, A. et al. On some structural and evolutionary aspects of rDNA amplification in oogenesis of Trachemys scripta turtles. Cell Tissue Res 383, 853–864 (2021). https://doi.org/10.1007/s00441-020-03282-x

PY - 2021/2

Y1 - 2021/2

N2 - The features of rDNA amplification have been studied in oocytes of the red-eared slider Trachemys scripta using a number of specific histochemical and cytomolecular methods. A single nucleolus in early diplotene oocytes is associated with the nucleolus organizer region (NOR). With oocyte growth, the number of nucleoli increases dramatically and reaches hundreds by the lampbrush chromosome stage (pre-vitellogenesis). RNA-polymerase I, fibrillarin, and PCNA immunodetection in the amplified nucleoli and FISH of the 5'ETS probe to the oocyte nuclear content suggest pre-rRNA and rDNA synthesis in the nucleoli at all stages studied. This implies a continuous reproduction of the nucleoli during oocyte development from early diplotene up to vitellogenesis. The data obtained offer a different way for rDNA amplification and formation of extrachromosomal nucleoli in turtle oocytes compared with the amplified nucleoli formation in amphibian and fish oocytes. In the Sauropsida clade of Archelosauria, which includes turtles, crocodiles, and birds, rDNA function is known to be suppressed in avian oogenesis during the lampbrush stage (Gaginskaya et al. in Cytogenet Genome Res 124:251-267, 2009).

AB - The features of rDNA amplification have been studied in oocytes of the red-eared slider Trachemys scripta using a number of specific histochemical and cytomolecular methods. A single nucleolus in early diplotene oocytes is associated with the nucleolus organizer region (NOR). With oocyte growth, the number of nucleoli increases dramatically and reaches hundreds by the lampbrush chromosome stage (pre-vitellogenesis). RNA-polymerase I, fibrillarin, and PCNA immunodetection in the amplified nucleoli and FISH of the 5'ETS probe to the oocyte nuclear content suggest pre-rRNA and rDNA synthesis in the nucleoli at all stages studied. This implies a continuous reproduction of the nucleoli during oocyte development from early diplotene up to vitellogenesis. The data obtained offer a different way for rDNA amplification and formation of extrachromosomal nucleoli in turtle oocytes compared with the amplified nucleoli formation in amphibian and fish oocytes. In the Sauropsida clade of Archelosauria, which includes turtles, crocodiles, and birds, rDNA function is known to be suppressed in avian oogenesis during the lampbrush stage (Gaginskaya et al. in Cytogenet Genome Res 124:251-267, 2009).

KW - Extrachromosomal nucleoli

KW - Oocytes

KW - rDNA amplification

KW - Red-eared slider

KW - Reptilia

KW - LAMPBRUSH CHROMOSOMES

KW - RNA

KW - MORPHOLOGICAL-CHANGES

KW - AMPLIFIED NUCLEOLI

KW - POLYMERASE I

KW - OVARIAN-FOLLICLES

KW - DNA

KW - TURTLE

KW - RIBOSOMAL GENE AMPLIFICATION

KW - OOCYTES

UR - http://www.scopus.com/inward/record.url?scp=85090446247&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/01490a53-e2f1-3885-af23-e2ee10036154/

U2 - 10.1007/s00441-020-03282-x

DO - 10.1007/s00441-020-03282-x

M3 - Article

C2 - 32897424

AN - SCOPUS:85090446247

VL - 383

SP - 853

EP - 864

JO - Cell and Tissue Research

JF - Cell and Tissue Research

SN - 0302-766X

IS - 2

ER -