Lec 7 - Mentrual cycle

Question 1

How many couples are infertile?

Answer 1

1/6

Unexplained 28%
Male factor 21%
Ovulatory 18%
Tubal damage 14%
Endometriosis 9%
Coital problems 5%
Other 5%

Question 2

What is the walls of uterus composed of?

Answer 2

Endometrium
Myometrium
Perimetrium

Question 3

What is the 3 phases of menstrual cycle?

Answer 3

Proliferative,
secretory,
menstrual

Window of implantation is 20-24 days

Question 4

What is the roles of endometrium and explain how this is achieved.

Answer 4

Site of implantation.
Begins by attachment of the blastocyst through the outer trophoblast cells to the uterine lining

Trophoblast cells differentiate and invade the uterine endometrium

Blastocyte moves into the endometrium and is partially buried, after implantation fully buries in the endometrium

Question 5

What are the effects of estrogen and progesterone?

Answer 5

Estrogen - Proliferation

Progesterone - differentiation

Question 6

What is a trophoblast?

Answer 6

Cell formation on a blastocyst which provide nutrients

Question 7

What is the significance of L-selectin ligands?

Answer 7

Interaction between trophoblast and endometrium.

There are 2 known:
HECA 452 and MECA 79

Question 8

What is the significance of MECA 79?

Answer 8

Expressed highly in FERTILE women

Question 9

What is polycystic ovary syndrome (PCOS)?

Answer 9

Cystic ovaries
Irregular ovulation and menses
Obesity
Insulin resistant
Acne and hirsutism
High androgens

Question 10

What is Endometriosis?

Answer 10

Nonmalignant disorder where functional endometrium is outside the uterus

Question 11

What is the significance of HECA 452?

Answer 11

Predominant in infertile women, but not found under unexplained infertility

Question 12

What is the enzyme used to convert HECA 452 into MECA 79?

Answer 12

Sulfotransferase (GlcNAc6ST-2)

Question 13

What protein in the endometrium is present in binding L-selectin ligands?

Answer 13

Mucins

Highly glycosylated, high MW glycoproteins (integral)

abundant in endometrium in particular MUC1 and first molecule that embryo encounters. MUC1 repels embryo, directing embryo to sire rich in pinopods

contains the L-selectin epitope MECA 79

Question 14

Outline the structure of MUC1 protein (30nm)

Answer 14

N terminal - adhesion
Single membrane spanning domain
C-terminal - transcription factor

Question 15

Outline the genomics of MUC1 gene

Answer 15

type1 transmembrane glycoprotein

7 exons, 4 to 7kb depending on variable number tandem repeats in exon 2

regulatory site for estrogen binding and progesterone complexes

both alleles are CO-DOMINANTLY expressed