title: Failure of spermatogenesis in mouse lines deficient in the Na(+)-K(+)-2Cl(-) cotransporter.
abstract: The Na(+)-K(+)-2Cl(-) cotransporter (NKCC1) carries 1 molecule of Na(+) and K(+) along with 2 molecules of Cl(-) across the cell membrane. It is expressed in a broad spectrum of tissues and has been implicated in cell volume regulation and in ion transport by secretory epithelial tissue. However, the specific contribution of NKCC1 to the physiology of the various organ systems is largely undefined. We have generated mouse lines carrying either of 2 mutant alleles of the Slc12a2 gene, which encodes this cotransporter: a null allele and a mutation that results in deletion of 72 amino acids of the cytoplasmic domain. Both NKCC1-deficient mouse lines show behavioral abnormalities characteristic of mice with inner ear defects. Male NKCC1-deficient mice are infertile because of defective spermatogenesis, as shown by the absence of spermatozoa in histological sections of their epididymides and the small number of spermatids in their testes. Consistent with this observation, we show that Slc12a2 is expressed in Sertoli cells, pachytene spermatocytes, and round spermatids isolated from wild-type animals. Our results indicate a critical role for NKCC1-mediated ion transport in spermatogenesis and suggest that the cytoplasmic domain of NKCC1 is essential in the normal functioning of this protein.
authors.affiliation: Curriculum in Genetics, Department of Medicine, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina 27599, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Pace
authors.forename: E
authors.initials: E
authors.lastname: Lee
authors.forename: K
authors.initials: K
authors.lastname: Athirakul
authors.forename: T M
authors.initials: TM
authors.lastname: Coffman
authors.forename: D A
authors.initials: DA
authors.lastname: O'Brien
authors.forename: B H
authors.initials: BH
authors.lastname: Koller
mesh_terms: D000818:Animals; D001794:Blood Pressure; D002352:Carrier Proteins / Q000235:genetics*; D002712:Chlorides / Q000378:metabolism*; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology; D005838:Genotype; D007248:Infertility, Male; D007677:Kidney Function Tests; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D008817:Mice, Mutant Strains; D009994:Osmolar Concentration; D011188:Potassium / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012964:Sodium / Q000378:metabolism*; D028021:Sodium-Potassium-Chloride Symporters; D013091:Spermatogenesis / Q000235:genetics*; D013599:Systole; D013737:Testis / Q000033:anatomy & histology; D014556:Urine / Q000502:physiology
chemical_list: D002352:Carrier Proteins; D002712:Chlorides; D008565:Membrane Proteins; D028021:Sodium-Potassium-Chloride Symporters; D012964:Sodium; D003894:Deamino Arginine Vasopressin; D011188:Potassium