Genetic dosage and position effect of small supernumerary marker chromosome (sSMC) in human sperm nuclei in infertile male patient.

Chromosomes occupy specific distinct areas in the nucleus of the sperm cell that may be altered in males with disrupted spermatogenesis. Here, we present alterations in the positioning of the human chromosomes 15, 18, X and Y between spermatozoa with the small supernumerary marker chromosome (sSMC; sSMC(+)) and spermatozoa with normal chromosome complement (sSMC(-)), for the first time described in the same ejaculate of an infertile, phenotypically normal male patient. Using classical and confocal fluorescent microscopy, the nuclear colocalization of chromosomes 15 and sSMC was analyzed.

X-linked TEX11 mutations, meiotic arrest, and azoospermia in infertile men.

Background: The genetic basis of nonobstructive azoospermia is unknown in the majority of infertile men.

Methods: We performed array comparative genomic hybridization testing in blood samples obtained from 15 patients with azoospermia, and we performed mutation screening by means of direct Sanger sequencing of the testis-expressed 11 gene (TEX11) open reading frame in blood and semen samples obtained from 289 patients with azoospermia and 384 controls.

Results: We identified a 99-kb hemizygous loss on chromosome Xq13.

High quality RNA in semen and sperm: isolation, analysis and potential application in clinical testing.

Purpose: Male infertility is a complex health condition. To our knowledge there are no molecular biomarkers of male infertility. Sperm RNA is a potential biomarker for detecting sperm abnormalities and viability at infertility clinics.

Molecular phylogenetics of the glass frog Hyalinobatrachium orientale (Anura: Centrolenidae): evidence for Pliocene connections between mainland Venezuela and the island of Tobago.

The presence of Hyalinobatrachium orientale in Tobago and in northeastern Venezuela is puzzling as this species is unknown from the island of Trinidad, an island often hypothesized to be a stepping-stone for the mainland fauna to colonize Tobago. A period of extended isolation on Tobago could result in the Hyalinobatrachium population becoming distinct from the mainland H. orientale.

UBE2B mRNA alterations are associated with severe oligozoospermia in infertile men.

Oligozoospermia (low sperm count) is a common semen deficiency. However, to date, few genetic defects have been identified to cause this condition. Moreover, even fewer molecular genetic diagnostic tests are available for patients with oligozoospermia in the andrology clinic.