Expression of CD44 in sheep oocytes and preimplantation embryos

Abstract

ABSTRACT. The CD44 family belongs to a larger group of hyaluronic acid-binding proteins and plays important roles in oocyte maturation, fertilization and preimplantational embryo development. We analyzed the CD44 receptor in sheep oocytes and embryos. Immature oocytes (N = 66) were obtained from a local abattoir; mature oocytes (N = 35) and embryos (N = 41) were obtained by laparotomy from adult hair ewes submitted to ovarian stimulation treatment. The CD44 mRNA was detected by hemi-nested PCR, after reverse transcription, while proteins were located by indirect immunofluorescence, using anti-human CD44 monoclonal antibody. Human lymphocytes and immature bovine oocytes were used as positive and negative controls, respectively. Assessment of the oocyte nuclear stages as well as classification of the embryonic development stage were made with Hoechst 33342 staining. Indirect immunofluorescence detected CD44 expression on the surface of mature oocytes and embryos; immature oocytes did not take up the stain. These findings were supported by the RT-PCR data, which showed no mRNA templates for CD44, even after two consecutive amplifications, in material from immature oocytes and cumulus cells. The CD44 amplicons were detected after a second hemi-nested PCR in mature oocytes and embryos. The finding of CD44 in mature oocytes and preimplantational embryos could reflect the expression profile of hyaluronic acid during terminal folliculogenesis and preimplantational embryo development in sheep.

Cd44 gene expression in mature and immature oocytes and fetus of Kermani and Baluchi sheep, and Rayeni and Tali goats

“…This is logical since immature oocytes need to get in touch with nearby granulose cells to allow nutrient passage and to get good development. This agrees with previous data on other mammalian class such as porcine (Campbell et al, 1995) and bovine (Luz et al, 2012), in which CD44 in immature oocytes was not detected.…”

“…It is now recognized that CD44 influences the growth of the cumulus cells throughout the oocyte maturation (oeplia et al, 2012), leading to fertility and excellence of oocytes (Luz et al, 2012). As the hyaluronan-CD44 communication is concerned in the introduction of meiotic recommencement, it was supposed that this receptor was expressed in the oocytes.…”

“…This information shows that CD44 is expressed throughout the maturation procedure, which suggests its significance in this phase. It is reasonable to assume that HA profile is directly proportional to the amount of CD44 in somatic cells surrounding the rising oocyte (Luz et al, 2012). There is a whole connection loss of cumulus growth in cumulus-oocyte complexes (COCs) and oocyte meiotic series (Allworth and Albertini, 1993).…”

“…Glycosaminoglycans (GAGs) play a main role in the proliferation and differentiation of a variety of cell types (Luz et al, 2012). The communication between the granulosa cells and the adjoining is vital for the attainment of oocyte aptitude (Assidi et al, 2008).…”

Identification of marker genes in diabetic wounds by DNA microarray study

“…In humans, the CD44 antigen is encoded by the CD44 gene on chromosome 11 (Haynes et al, 1989) and plays important roles in oocyte maturation, fertilization and preimplantational embryo development (Luz et al, 2012). CD44 can also affect the regulation of the wound repair process.…”