Insect Ooogenesis- L14

Question 1

What are kernels?

Answer 1

GRNs for a given development function not used elsewhere in development.

Question 2

What does GRN stand for?

Answer 2

Gene Regulatory Network

Question 3

GRNS have what type of wiring?

Answer 3

Recursive Wiring

Question 4

What does recursive wiring mean?

Answer 4

Products of many genes are required for the function of the kernel.

Question 5

What would happen if there was interference with expression of anyone one kernel gene?

Answer 5

This would destroy the function of the entire kernel and have severe developmental consequences

Question 6

What does oogenesis mean

Answer 6

egg formation

Question 7

How does the oocyte split?

Answer 7

Through meiosis to form a haploid cell, the ovum.

Question 8

What is a feature of a mature ovum?

Answer 8

Yolk containing vitellin

Question 9

Vitellogenesis may occur through what?

Answer 9

A lengthened prophase of meiosis

Question 10

What happens during vitellogenesis?

Answer 10

The process of yolk formation via nutrients being deposited in the oocyte

Question 11

Ooogenesis can be categorised by the relationship of the oocyte to what cells?

Answer 11

solitary, follicular, nutrimentary

Question 12

By what pathway can oogenesis be catgeorised?

Answer 12

The synthetic pathway for the stored yolk in the cytpolasm

• autosynthetic oogenesis
• heterosynthetic oogenesis

Question 13

What cells are missing in solitary oogenesis?

Answer 13

Follicle and nurse cells

Question 14

What is different about follicular oogenesis?

Answer 14

oocytes are associated with a covering of somatic cells

EXAMPLE: In the tunicate ascidella aspersa

Question 15

What type of ovaries do locusts have?

Answer 15

Panoistic ovaries (with follicle cells) that develop within ovarioles.

Question 16

What cells are oocytes associated with in nutrimentary oogenesis?

Answer 16

Nurse cells (sister cells)

Question 17

What type of development do drosophillia ovary show?

Answer 17

polytropic meroistic development, in which oogonia divide into oocyte and nurse cells

Question 18

What is autosynthesis?

Answer 18

The synthesis of yolk and other stored materials by the oocyte itself.

Question 19

What is heterosynthesis?

Answer 19

The synthesis of yolk proteins by other, non-germ cells, characterised by the uptake of vitellogenin (later stored as vitellin)

Question 20

Who created the idea of regional organisation?

Answer 20

Nusslein-volhard and Wieschaus.

Question 21

What was the procedure for regional organisation experiment?

Answer 21

Treated flies with chemical mutagen and classified lethal/near lethal mutants dependent on effects on bristle patterns and segmental organisation.

Question 22

What were the findings of the regional organisation experiment?

Answer 22

Lead to term MATERNAL EFFECT GENES.
Larvae often appeared to have missing segments. Some mutations were dependent on genotype of mother - maternal factors are deposited in oocyte. Such gened termed MATERNAL EFFECT GENES, expressed in ovarian tissues during oogenesis.