| MOMX | macroorchidism-marker X chromosome [syndrome] |
|---|---|
| MTACR | multiple tumor-associated chromosome region |
| 2n | haploid chromosome; diploid |
| PCC | Pasteur Culture Collection; percutaneous cecostomy; pheochromocytoma; phosphate carrier compound; pl... |
| pcc | premature chromosome condensation |
| Y chromosome | <genetics> The small chromosome that is male-determining in most mammal species and found only in the heterogametic sex. Thus in mammals the male has one Y chromosome and one X chromosome. One region of the Y chromosome, the pseudoautosomal region, is homologous to and pairs with the X chromosome. The primary determinant of male sexual development is found on the unpaired, differentiated segment of the Y chromosome. It carries few other genes besides those dictating sperm development and triggering appropriate hormonal output. (18 Nov 1997) |
|---|---|
| yeast artificial chromosome | <molecular biology> A vector system that allows extremely large segments of DNA to be cloned. Useful in chromosome mapping, contiguous yeast artificial chromosomes covering the whole Drosophila genome and certain human chromosomes are available. Acronym: YAC (15 Nov 1997) |
| Z chromosome | <genetics> This is a sex chromosome in certain animals such as chickens and moths. In the Z chromosome karyotype, females are heterogametic, so males are ZZ and females are WZ. (11 May 1997) |
| unpaired chromosome | A chromosome existing without its normal homologous chromosome; at the reduction division of gametogenesis an accessory chromosome is likely to be included in one daughter cell and not in the other, but may be lost completely by lagging behind on the equatorial plate. Synonym: monosome, odd chromosome, unpaired allosome, unpaired chromosome. (05 Mar 2000) |
| lampbrush chromosome | <cell biology> Large chromosomes (as long as 1mm), actually meiotic bivalents, seen during prophase of the extended meiosis in the oocytes of some Amphibia. Segments of DNA form loops in pairs along the sides of the sister chromosomes, giving them a brush like appearance. These loops are not permanent structures but are formed by the unwinding of chromomeres and represent sites of very active RNA synthesis. (27 Jun 1999) |
| late replicating chromosome | A chromosome (often anomalous) that is shown, e.g., by incorporation of a labelled nucleotide, to undergo delayed duplication preliminary to mitosis; formerly used as a means of distinguishing members of a group of chromosome's. (05 Mar 2000) |
| fragile x chromosome | X chromosome with a fragile site associated with a frequent form of mental retardation. The fragile X chromosome was first sighted by Herbert A. Lubs in 1969. The fragile X is also called FRAXA (the second A signifies it was the first FRAgile site found on the X chromosome). It is due a trinucleotide repeat (a recurring motif of 3 bases) in the DNA at that spot. (12 Dec 1998) |