Gene amplification of the Menkes (MNK; ATP7A) P-type ATPase gene of CHO cells is associated with copper resistance and enhanced copper efflux.

Three copper-resistant variants of cultured Chinese hamster ovary (CHO) cells were isolated and each was shown to accumulate less intracellular copper than the parental cells when grown in copper-supplemented media. The reduced copper accumulation was related to enhanced copper efflux. As cultured cells from patients with Menkes disease (mutations in MNK; ATP7A gene) accumulate copper, probably due to defective copper efflux, we investigated the possible role of the MNK gene in the molecular basis of copper resistance.

Region-specific cosmids and STRPs identified by chromosome microdissection and FISH.

A strategy for identifying short tandem repeat (STR)-containing cosmid clones from a specific chromosomal region is described. The approach is based on the use of uncloned, PCR-amplified DNA derived from chromosome microdissection and pooled groups of STR sequences as hybridization probes to screen a cosmid library. Cosmid clones that display a positive signal common to both hybridizations are then characterized for repeat length polymorphisms.

Localization of the human HTF4 transcription factors 4 gene (TCF12) to chromosome 15q21.

Identification and localization of genes that encode regulators of transcription could provide landmarks for functional analysis of the human genome. Toward this goal, we examined a panel of somatic cell hybrids and assigned the gene (TCF12) encoding the helix-loop-helix transcription factors 4 (HTF4) to chromosome 15. Fluorescence in situ hybridization further localized TCF12 to chromosome 15q21.

Multicolor FISH mapping of YAC clones in 3p14 and identification of a YAC spanning both FRA3B and the t(3;8) associated with hereditary renal cell carcinoma.

Human chromosome band 3p14 contains two tightly linked cytogenetic markers of broad interest, FRA3B and the t(3;8) breakpoint associated with hereditary renal cell carcinoma (RCC). The common fragile site at 3p14.2 (FRA3B) is the most sensitive site on normal human chromosomes to breakage when DNA replication is perturbed by aphidicolin or folate stress.