Pregled bibliografske jedinice broj: 26571
Size variation and peculiar behaviour of nucleolar organizer region in Quercus species
Size variation and peculiar behaviour of nucleolar organizer region in Quercus species // Plant Cytogenetics / Maluszynska, Jolanta (ur.).
Katovice: Wydawnictwo Uniwersytetu Śląskiego, 1998. str. 131-140 (predavanje, međunarodna recenzija, cjeloviti rad (in extenso), znanstveni)
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Naslov
Size variation and peculiar behaviour of nucleolar organizer region in Quercus species
Autori
Papeš, Dražena ; Zoldoš, Vlatka ; Besendorfer, Višnja ; Šiljak-Yakovlev, Sonja
Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni
Izvornik
Plant Cytogenetics
/ Maluszynska, Jolanta - Katovice : Wydawnictwo Uniwersytetu Śląskiego, 1998, 131-140
Skup
Plant Cytogenetics Spring Symposium
Mjesto i datum
Cieszyn, Poljska, 19.05.1997. - 22.05.1997
Vrsta sudjelovanja
Predavanje
Vrsta recenzije
Međunarodna recenzija
Ključne riječi
NOR; detached satellite; oaks; Quercus species; meiosis
Sažetak
Heteromorphy of the nucleolar organizing region (NOR) in the karyotypes of Q. petreae, Q. robur and Q. pubescens were noticed. This heteromorphy concerned size variation and rarely number variation of NORs in the karyotypes of different individuals of the same species. In general, Quercus species contain one pair of satellite chromosomes (SAT-chromosomes) bearing NORs on the terminal position. In the karyotypes of some individuals NORs were frequently detached from SAT-chromosomes and appeared as free spherical bright yellow fragments in the cells after chromomycin staining. Because of this behaviour we had suspected them as "B-chromosomes" in our previous report. In mitotic anaphase, such fragments formed bridges of extended sticky connecting threads with thier SAT-chromosomes of were lagging after anaphase group but it seemed that they were never elimated . On the other hand, fragments never occurred free in meiosis and two chromomycin positive dots were always located on the terminal site of the two chromosomes forming a bivalent. Recently applied fluorescent hybridisation in situ revealed hybridization signals of 18S RNA probe on the two SAT-chromosomes or fragments, respectively, proving its role as nucleolar organizers. Present investigation carry out NOR's size variation and frequency of detached NORs in comparison with NORs located on SAT-chromosomes in different individuals of the same species.
Izvorni jezik
Engleski
Znanstvena područja
Biologija
