ABSTRACT
Heterotrimeric guanine nucleotide binding proteins (G proteins) transduce extracellular signals received by transmembrane receptors to effector proteins. Each subunit of the G protein complex is encoded by a member of one of three corresponding gene families. Currently, 16 different members of the alpha subunit family, 5 different members of the beta subunit family, and 11 different members of the gamma subunit family have been described in mammals. Here we have identified and characterized Bacterial Artificial Chromosomes (BACs) containing the human homologs of each of the alpha, beta, and gamma subunit genes as well as a G alpha11 pseudogene and a previously undiscovered G gamma5-like gene. The gene structure and chromosome location of each gene was determined, as were the orientations of paired genes. These results provide greater insight into the evolution and functional diversity of the mammalian G protein subunit genes.
Subject(s)
GTP-Binding Proteins/genetics , Amino Acid Sequence , Chromosome Mapping , Exons , Humans , Introns , Molecular Sequence Data , Multigene Family , Sequence Homology, Amino AcidABSTRACT
OBJECTIVE: To measure and compare sperm hyperactivation (HA) and associated motility parameters using the CellTrak (Motion Analysis Corporation, Santa Rosa, CA) and Cellsoft (Cryo Resources, New York, NY) Computer-Assisted Sperm Analysis (CASA) Systems. The accuracy of the CellTrak system also was assessed by repeated measurements of the same sample. SETTING: A university-affiliated tertiary care center. PATIENTS: Normal healthy volunteers. MAIN OUTCOME MEASURES: We assessed sperm motion parameters and HA. RESULTS: The measurements of percent spermatozoa with star and/or transitional pattern of HA showed high within-sample variations, especially in samples showing low levels of percent spermatozoa with HA. This was due to the comparatively low numbers of hyperactivated spermatozoa that were present and counted in a sample. Excellent agreement between the two systems was observed for all parameters except for measurements of curvilinear velocity, percent spermatozoa with star-spin hyperactivity, and percent spermatozoa with transitional hyperactivity. The difference might be due to CellTrak's higher level of accuracy in determining velocity. CONCLUSIONS: The CellTrak system effectively measures human sperm HA provided adequate numbers of motile spermatozoa are analyzed. Although it suffers from the same limitations common to all CASA systems, it is more accurate than the Cellsoft system.
