Repro test 4 (4): male assisted

Vocabulary practice flashcards covering male assisted reproductive technologies, semen extension, cryopreservation, ICSI, spermatogonial stem cell transplantation, and male contraceptive methods.

Artificial Insemination (AI)

A common reproductive technology utilized across livestock species to maximize the genetic contribution of elite sires by collecting, extending, and depositing semen into the female reproductive tract.

Semen Extender

A liquid diluent added to an ejaculate to nourish sperm cells, maintain pH balance, prevent bacterial growth, and, when desired, facilitate cryopreservation for long-term storage or shipment.

Nutrient Source (in Semen Extender)

A primary component of semen extenders—typically egg yolk, buttermilk, or glucose—that provides metabolic energy substrates to sustain sperm viability and motility outside the body.

pH Buffer (in Semen Extender)

Chemical agents such as sodium citrate ($\text{Na Citrate}$) or sodium phosphate ($\text{Na Phosphate}$) added to semen extenders to neutralize metabolic byproducts, prevent pH shock, and maintain a hospitable environment for sperm.

Antibiotics (in Semen Extender)

Additives such as penicillin and streptomycin included in semen extenders to eliminate bacteria introduced during non-sterile collection and prevent uterine infections when AI bypasses the natural cervical barrier.

Uterine Infection (AI Complication)

A condition resulting from non-sterile semen entering the uterus that prevents pregnancy and can disrupt luteolysis, causing a female to cease cycling and falsely mimic pregnancy.

Glycerol

A cryoprotectant added as a fourth component in frozen semen extenders that enters sperm cells and draws out water, preventing ice crystal expansion and plasma membrane rupture during freezing.

Cryopreservation Species Disparity

The physiological variability in freezing success across livestock: bull semen cryopreserves continuously and successfully, sheep and goat semen has intermediate success, while boar semen cannot freeze and stallion semen cryopreserves poorly.

Sexed Semen

Semen sorted into X-chromosome (female) and Y-chromosome (male) bearing sperm populations using a DNA-binding vital dye, laser excitation, and flow cytometry sorting.

Viable Sperm Sorting System

A flow cytometric apparatus that measures differential fluorescence emitted by vital-dye-stained X and Y sperm exposed to a laser, assigning droplets an electrical charge to deflect them into separate collection vessels.

First-Service Heifer Strategy (Sexed Semen)

The management practice in dairies of breeding virgin heifers with sexed semen because non-lactating heifers have higher baseline pregnancy rates and represent the herd's best genetic potential.

Intracytoplasmic Sperm Injection (ICSI)

An assisted reproductive procedure where a single sperm cell with low motility is directly injected through the zona pellucida into the cytoplasm of a mature oocyte using a microscopic glass needle.

Polar Body

A small cellular structure extruded by an oocyte that visually confirms it has successfully completed meiosis and is ready for fertilization.

Equine ICSI

The clinical application of ICSI in horses, adopted widely because stallion semen cryopreserves poorly and conventional equine in vitro fertilization (IVF) is historically ineffective.

Dr. Catherine Hinrichs

The reproductive veterinary pioneer who developed and established the clinical application of intracytoplasmic sperm injection (ICSI) in horses at Texas A&M University.

Spermatogonial Stem Cell Transplantation

The isolation of regenerative spermatogonial stem cells from a donor male's testes and their transplantation into the seminiferous tubules of a recipient male to initiate donor-derived spermatogenesis.

Blood-Testis Barrier (Transplantation Role)

A specialized physiological boundary creating an immune-privileged environment in the testes that prevents host immune cells from detecting and rejecting allogeneic transplanted spermatogonial stem cells.

CRISPR-Cas9 in Recipient Sire Production

A gene-editing innovation used to engineer embryos that develop into mature male recipient animals inherently lacking endogenous spermatogonial stem cells, eliminating the need for toxic ablative chemotherapy.

Transgenics

Of, relating to, or being an organism whose genome has been deliberately altered through the artificial transfer of a gene or genes from another species or breed.

Male Contraceptive Criteria

The requirement that a male contraceptive must reliably and reversibly halt fertility without compromising secondary sexual characteristics, testosterone production, mating behavior, or libido.

Nifedipine

A calcium channel blocker used for hypertension and migraines that acts as a male contraceptive by stiffening sperm membranes with cholesterol and preventing mannose lectin translocation to the surface, inhibiting zona pellucida binding.

Mannose Lectin

A critical sperm surface receptor molecule required for recognizing and binding to the outer zona pellucida of the oocyte during fertilization.

Dry Orgasm Pill

A high blood pressure and schizophrenia medication side effect discovered by Drs. Amobi and Smith that inhibits autonomic smooth muscle contractions of the vasa deferentia, causing ejaculates to lack sperm.

Ultrasound Contraception

A physical contraceptive method utilizing sound waves in a warm water bath to heat the scrotum and alter ion exchange between seminiferous tubules and the rete testis, halting sperm production.

Vasalgel

A reversible polymer gel injected into the lumen of the vas deferens that solidifies to mechanically block sperm passage and can be dissolved and flushed out with a subsequent injection to restore fertility.

RISUG®

Reversible Inhibition of Sperm Under Guidance; a long-acting injectable polymer technology developed in India that coats the inner walls of the vas deferens to provide reversible male contraception.