A case of perosomus elumbis in a Holstein calf.

Perosomus elumbis is an occasionally found congenital anomaly of unknown etiology and is characterized by partial or complete agenesis of lumbar, sacral and coccygeal vertebrae and ankylosis of the hindlimbs. A 2-day-old female Holstein calf presented nearly normal forelimbs but flexure and ankylosis of the hindlimbs. The vertebrae and pelvic malformations and agenesis were radiographed and then necropsied.

Generation of cloned transgenic pigs rich in omega-3 fatty acids.

Meat products are generally low in omega-3 (n-3) fatty acids, which are beneficial to human health. We describe the generation of cloned pigs that express a humanized Caenorhabditis elegans gene, fat-1, encoding an n-3 fatty acid desaturase. The hfat-1 transgenic pigs produce high levels of n-3 fatty acids from n-6 analogs, and their tissues have a significantly reduced ratio of n-6/n-3 fatty acids (P < 0.

Production of a transgenic piglet by a sperm injection technique in which no chemical or physical treatments were used for oocytes or sperm.

As a method of producing transgenic animals, spermatozoa have been used to fertilize mammalian oocytes through natural copulation, artificial insemination (AI), and in vitro fertilization (IVF). Our objective was to produce live piglets expressing the enhanced green fluorescent protein (eGFP) by the modified ICSI procedure based on Yong et al. (2003) (Hum.

RETRACTED: Cdx2 gene expression and trophectoderm lineage specification in mouse embryos.

Controversy exists as to whether individual blastomeres from two-cell-stage mouse embryos have identical developmental properties and fate. We show that the transcription factor Cdx2 is expressed in the nuclei of cells derived from the late-dividing but not the first-dividing blastomere of two-cell embryos and, by lineage tracing and RNA interference knock-down experiments, that this lagging cell is the precursor of trophectoderm. Cdx2 mRNA is localized toward the vegetal pole of oocytes, reorients after fertilization, and becomes concentrated in the late-dividing, two-cell-stage blastomere.

Effect of centrifugation and electrical activation on male pronucleus formation and embryonic development of porcine oocytes reconstructed with intracytoplasmic sperm injection.

Oocyte centrifugation and electrical activation are commonly used in intracytoplasmic sperm injection (ICSI) of bovine and porcine oocytes, to facilitate visual identification of sperm release into the ooplasm and to support oocyte activation following injection with tail membrane-damaged sperm. The present study evaluated the necessity of these steps in porcine modified ICSI. In the first series of experiments, in vitro-matured gilt oocytes with or without centrifugation were injected with head membrane-damaged spermatozoa aspirated tail first.

Sperm movement in the ooplasm, dithiothreitol pretreatment and sperm freezing are not required for the development of porcine embryos derived from injection of head membrane-damaged sperm.

The present study investigated the correlation of sperm movement in the ooplasm, pretreatment of sperm with dithiothreitol (DTT) and sperm freezing with the development of porcine embryos derived from modified intracytoplasmic sperm injection (ICSI). In vitro, matured gilt oocytes without centrifugation were injected with head membrane-damaged spermatozoa aspirated tail-first. In Exp.

A modified method for ICSI in the pig: injection of head membrane-damaged sperm using a 3-4 micro m diameter injection pipette.

Background: Conventional ICSI to date was focused only on tail membrane damage to achieve sperm immobilization and disruption of the plasma membrane, even though liberation of soluble sperm factors is achieved by disruption of the sperm head membrane.

Methods: A modified method for ICSI was developed: head membrane-damaged spermatozoa aspirated tail or head first were injected into the ooplasm using a 3-4 micro m diameter injection pipette connected to an open-ended aspiration tube regulated by mouth. The efficiency of this modified ICSI was compared with that of conventional ICSI and IVF.