摘要:

T(5;19)1Wh × T(9;19)163H F1 hybrids were used in four types of crosses to produce fetuses with trisomy 19. Trisomy was more frequent early in gestation (7.9–23.0 %) than after 16½ days (4.5–16.9 %) and was associated with many non-viable implantations. Male hybrids produced significantly more trisomics than female hybrids in crosses with NIH GP mice terminated early in gestation. In fetuses beyond 16 V2 days, isolated cleft palate was consistently associated with trisomy 19. It was found only in trisomics carrying one T1Wh and two T163H translocations, although trisomics with one T163H and two T1Wh or with single T163H and T1Wh translocations were also produced. These and other observations demonstrate the effects of genetic background upon frequency of trisomy, survival of conceptuses, and phenotype of trisomic fetuses. These effects, as well as trans-location-specific meiotic mechanisms, must be considered when mouse translocation trisomy is compared with that of h

ISSN:1424-8581    

DOI:10.1159/000130274

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

Weights of viable trisomic mouse fetuses and placentas were compared with those of normal littermates between 12½ and 19½ days’ gestation. Mean trisomic fetal and placental weights were below normal weights at all stages. Differences in mean body weight were consistently significant, whereas those in placental weight varied. Trisomic fetuses of a specific karyotype predisposing to cleft palate were not smaller than trisomics of two other karyotypes, suggesting that a greater generalized growth lag was not responsible for the cleft palate. At each developmental stage, ratios of placental to body weights of normal and trisomic mice were similar. Sections of trisomic organs showed only one specific change: excessive degeneration of oocytes in some trisomic ovaries. All of these findings are discussed in relation to other studies of fetal and placental weight in mice and to studies of the effects of trisomy upon human development in ut

ISSN:1424-8581    

DOI:10.1159/000130275

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

In contrast to findings in many other species, the centromeric heterochromatin in cattle, goats, and sheep is unstained when the C-band method of Arrighi and Hsu (1971) is used. However, a modified C-band technique stains the centromeric heterochromatin strongly. This material also stains strongly with an acridine-orange reverse-banding method. The G-band patterns of some of the chromosomes of these three species show striking similarities, suggesting identity. Even some parts of the metacentric chromosomes of sheep, presumably resulting from Robertsonian fusions, can be identified as nearly unchanged chromosomes of the goat or of cattle. Auto-radiographic studies reveal that these centromeric regions replicate their DNA late in the S phase. Both 3H-thymidine and 3H-deoxycytidine are incorporated at these centromeric regions.

ISSN:1424-8581    

DOI:10.1159/000130276

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

Combined quinacrine fluorescent (Q-banding) and centromeric heterochromatin (C-banding) staining of metaphase chromosomes from the T199H heterozygous translocation stock of Mus musculus has shown that the break points in chromosomes 10 and 13 are located closer to each centromere than previously believed. Virtually all of chromosome 13, including the C-banding material, has been translocated to the distal region of chromosome 10. The presence of C-banding material in an interstitial location in the longer of the two translocation chromosomes provides a distinctive mitotic chromosome marker. Both the C-banding region and the euchromatic region of chromosome 13 are longer in the translocation chromosome than in the normal homolog. During meiosis in heterozygous males a chain of four chromosomes is the most common quadrivalent configuration. In the meiotic chromosome the amount of interstitial C-banding is markedly reduced from that seen in mitosis. C-banding is seen at the centromeric region of both the short translocation chromosome and the Y during meiosis but not mitosis.

ISSN:1424-8581    

DOI:10.1159/000130277

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

Portions of constitutive heterochromatin of the Chinese hamster Cricetulus griseus, do not appear to contain a disproportionately high amount of repeated DNA sequences. These specific regions are the long arm of the X chromosome, the entire Y chromosome, and the centromeric region of chromosome 10. Other heterochromatic areas of the Chinese hamster chromosomes showed localization of repetitious DNA.

ISSN:1424-8581    

DOI:10.1159/000130278

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

In this paper we describe an electrophoretic, autoradiographic technique for galactokinase which will separate the mouse, Chinese hamster, and human enzyme.

ISSN:1424-8581    

DOI:10.1159/000130279

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

G-banded karyotypes (413 in all) of the hypotetraploid mouse myeloma MOPC-21 and five cell lines isolated at different times, of the MOPC-315 tumor and a cell line, and of the X5563 tumor were compared. Two consistent markers and their possible origins were described. In addition to these characteristic myeloma markers, one homolog of chromosome pairs 3, 12, and 15 and one of the Xs may have been altered or lost before tetraploidization occurred. One cell line which had spontaneously become non-oncogenic with time in culture was studied before, during, and after this change. Associated karyotypic changes were: the addition of a large heterochromatic minute and a small marker, one half of which was centromeric heterochromatin; new rearrangements of chromosomes Nos. 3 and 12 and the X; and an apparent increase in immunogenicity of the non-oncogenic cell line.

ISSN:1424-8581    

DOI:10.1159/000130280

出版商:S. Karger AG    

年代:1974

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130281

出版商:S. Karger AG    

年代:1974

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130282

出版商:S. Karger AG    

年代:1974

数据来源: Karger