摘要:

Some aspects of the metabolism of proteins and of RNA have been investigated in normal rat liver and in two hepatomas, namely the slowly-growing well differentiated Morris hepatoma 5123, and the rapidly-growing strong anaplastic Yoshida ascites hepatoma A. H. 130. The results presented concern the rate of protein and RNA synthesis, the polysome patterns, the stability of messenger RNA and the changes of nuclear pulse labelled RNA as revealed by DNA/RNA hybridization.

ISSN:0008-7114    

DOI:10.1080/00087114.1970.10796358

出版商:Taylor & Francis    

年代:1970

数据来源: Taylor

摘要:

A cytological survey of a collection ofH. rosa-sinensis(x = 9) revealed the following chromosome numbers 2n=46, 54, 63, 68, 72, 77, 84, 90, 96, 112, 132 and 144. The 12 cytotypes could be divided into two distinct groups, a polyploid group (2n= 54, 63, 72, 90, 144) and a dysploid group (2n= 46, 68, 77, 84, 96, 112, 132). In the former, flower diameter was found to be directly proportional to chromosome number, while in the latter it was inconsistent.

ISSN:0008-7114    

DOI:10.1080/00087114.1970.10796359

出版商:Taylor & Francis    

年代:1970

数据来源: Taylor

摘要:

1.Naturally occurring triploids inCynodon dactylon(L.) Pers. were studied for the first time, together with a diploid clone.2.Chromosome associations were analysed and discussed with respect to the nature of triploidy involved.3.Frequencies of laggards and micronuclei in first and second divisions are discussed with reference to univalent behaviour.

ISSN:0008-7114    

DOI:10.1080/00087114.1970.10796360

出版商:Taylor & Francis    

年代:1970

数据来源: Taylor

摘要:

The number of nucleoli observed in telophases and early interphases of onion root meristem cells is generally two. The organization of up to eight nucleoli in multinucleate groups induced by a colchicine treatment, shows that the activity of a second set of nucleolar organizers, consisting of one pair of potential organizers per diploid nucleus, comes into play. The dynamics of these potencial organizers is discussed.

ISSN:0008-7114    

DOI:10.1080/00087114.1970.10796361

出版商:Taylor & Francis    

年代:1970

数据来源: Taylor

摘要:

The karyotypes and male meiosis of nine Hylidae and one Microhylidae are described. Those are: Hylidae —Hyla raniceps(2n= 24),Phrynohyas venulosa(2n= 24),Hyla crepitans(2n=24),Hyla polytaenia(2n=24),Hyla minuta(2n=30),Hyla rubicundula(2n=30),Hyla nana(2n= 30),Hyla fuscomarginata(2n=24),Hyla trachytorax(2n= 24); Microhylidae —Dermatonotus mülleri(2n=22). Male and female karyotypes are identical. The spermatocytes I of eight species exhibited ring bivalents with terminal chiasmata. Interstitial chiasmata were observed inH. rubicundulaandH. nana.No bivalent suggested by its morphology or behavior the presence of heteromorphic sex chromosomes.

ISSN:0008-7114    

DOI:10.1080/00087114.1970.10796362

出版商:Taylor & Francis    

年代:1970

数据来源: Taylor

摘要:

Nucleolar vacuoles in eight regions of the root apex ofZea mayshave been studied. The volume of the vacuoles ranges from about 1 μm3to 0.001 μm3with a mode value between 0.075 and 0.01 μm3. The number of vacuoles within a nucleolus ranges from 0–20 and is correlated with nucleolar volume. In all regions studied the average volume of the nucleolus occupied by vacuoles is about 3 percent. It is suggested that the metabolic capacity of the nucleolus may be reflected in the rate of formation of the vacuoles and the discharge of their contents to the cell.

ISSN:0008-7114    

DOI:10.1080/00087114.1970.10796363

出版商:Taylor & Francis    

年代:1970

数据来源: Taylor

摘要:

The relations between DNA replication and nuclear chromatin structure were studied in root tips ofAllium carinatumby autoradiography, using3H-thymidine as precursor. The findings give evidence for the existence of significant structural differences between nuclei in G1and in G2, and for DNA replication of heterochromatin in the condensed (= chromocenter) state.

ISSN:0008-7114    

DOI:10.1080/00087114.1970.10796364

出版商:Taylor & Francis    

年代:1970

数据来源: Taylor

摘要:

Chromosomal mechanisms involved in the evolution of the karyotype were examined in Chiroptera. In particular the Robertsonian process of centric fusion-fission was thoroughly studied. On the basis of karyological and morphological observations, the Authors aim to demonstrate that the Robertsonian change does not proceed in a single direction; it just provides a cytological basis for the onset of a genetic barrier. The importance of other chromosomal changes in the karyotypic evolution of Chiroptera has also been pointed out. A complete table of karyological data in Chiroptera is provided.

ISSN:0008-7114    

DOI:10.1080/00087114.1970.10796365

出版商:Taylor & Francis    

年代:1970

数据来源: Taylor

摘要:

A squash method for chromosomes from living and preserved Ascidians (Tunicata) has been established.

ISSN:0008-7114    

DOI:10.1080/00087114.1970.10796366

出版商:Taylor & Francis    

年代:1970

数据来源: Taylor

ISSN:0008-7114    

DOI:10.1080/00087114.1970.10796367

出版商:Taylor & Francis    

年代:1970

数据来源: Taylor