Canadian Health&Care; Mall

Animals This investigation was approved by the ethics committee of the Clinical Institute of Montreal and McGill University and was conducted according to accepted standards of animal experimentation. The FORKO mice were generated by homologous recombination as described by Dierich et al.. This alteration eliminates the entire repertoire of FSH-R forms, producing complete loss of hormone signaling. Breeding F2 heterozygous males and females produced mice of all three genotypes in the SV129 background. The animals were maintained under well-controlled conditions of temperature (22°C) and light (12L:12D), with food and water provided ad libitum. The primers and amplification conditions used for the multiplex polymerase chain reaction (PCR) to identify the phenotypes have been described in detail elsewhere. According to this protocol, a single PCR performed on each sample allowed unambiguous identification of +/+, +/—, and —/— mice. Routine Light and Electron Microscopic Methods A total of 16 mice at 3 and 6 mo of age (wild type, n = 4; FORKO, n = 4, for each age group) were used for detailed ultrastructural analyses of their testes. The mice were anesthetized by an intraperitoneal injection with sodium pentobarbital (Somnitol; MTC Pharmaceuticals, Hamilton, ON, Canada). Prior to perfusion, a hemostat was placed over the testicular vessels entering the left testis of each animal; this testis was removed, immersed in Bouin fixative and, after 10 min, cut in half and left in Bouin for 24 h. Thereafter, all the left testes were dehydrated in alcohol and subsequently embedded in paraffin.