The cohesion protein REC8 is involved in sister chromatid cohesion and aneuploidy in young versus old oocytes.

I have attached 2 attachments.

1. Rubric

2. Assignment Instructions

– 350 words total

– Claim (1-2 sentences), Evidence (1 paragraph), Explanation (1 paragraph)

– Examine all parts of the figure provided below on page 3

Please pay attention to rubric and instructions for maximize the grades.

Good Developing Not sufficient

2 1 0

1 0.5 0

Included where needed and with

proper format

Error(s) in format/usage (e.g. not

enough citations) Many errors in format/usage OR missing

Clear logical flow of ideas that is

easy to follow from start to finish Some parts unclear or hard to follow

Many instances where writing was

unclear and hard to follow

Little to no grammar or sentence

structure mistakes, no spelling

errors

Some grammar, sentence structure, or

spelling errors

Multiple of grammar, sentence structure,

or spelling errors

◻ Missing much or all of the

necessary data to support

claim(s)/includign far too much

irrelevant data

◻ Includes most of the necessary

data to support claim(s) OR includes

all relevant data + some irrelevant

data

Clarity of writing 1

Clarity of writing 2

Accurate ◻ Incorrect explanation, reasoning is

irrelevant to the data and/or claim

◻ Some inaccuracies in the

explanation

◻ Correctly connects data and

claim using logical explanations of

biology/genetics

Complete ◻ Reasoning is insufficient or

missing

◻ Some reasoning missing (e.g.

some evidence not justified)

◻ Includes all the necessary

reasoning to support claim(s)

◻ Some possible claims are

missing

◻ Includes all claims possible &

relevant from the given data

◻ Includes all necessary data to

support claim(s), and not

irrelevant data

CLAIM

Complete &

relevant

Component:

Missing or extremely incomplete

EVIDENCE

EXPLANATION (model):

connect evidence to the

underlying biology/genetics to

explain or hypothesize about

why these results exist. Connect

to claim and broader research

question

Citations & references

Accurate ◻ Inaccurate description of the data◻ Some inaccuracies ◻ Descriptions of the evidence

are accurate

Accurate

◻ No, the claim(s) does not fit the

data/does not answer research

question.

◻ Some of the claim(s) fits the

data/answers the research question.

◻ All of the claim(s) fit the data

and answer the research

question.

Complete

Bumwon Kwak (Brandon)

BICD 100

Prof. Mcdonnell

29 October 2017

Writing Assignment # 2

Claim: The cohesion protein REC8 is involved in sister chromatid cohesion and aneuploidy in young versus old oocytes.

Evidence: Aneuploidy is known to often result from chromosome misalignment at metaphases stages. From Fig. B, REC8 intensity is significantly decreased in old age. The deteriorated chromosome cohesion is a leading source of aneuploidy in oocytes in a natural aging mice model. In Fig. F, the interkinetochore distant apart, this happening at Metaphase I and II, showing decreased centromere cohesion. The levels of the meiotic cohesin protein REC8 are harshly decreased on chromosomes in oocytes from old (Jessberger, 2012).

Explanation: There is association among REC8, sister chromatid cohesion, and aneuploidy in young and old oocytes. In Fig. G, Oocytes show increased chromosome misalignment with age, as opposed to when oocytes have reduced misalignment to when young. Oocytes coming from young and aged SAM (senescence-accelerated mice) exhibit centromere linked protein-E (CENP-E) at centromeres of all chromosomes, comprising misaligned chromosomes from aged SAM. Oocytes are prone chromosome mis-segregation, and aneuploidy intensifies with age. As oocyte age surges sister chromatid cohesion is weakened or lost. Cohesion weakening seems to contribute considerably to age-dependent aneuploidy (Garcia-Cruz, 2010). Cohesion defects caused aneuploidies is showed through chromosome segregation dynamics at Anaphase I in live oocytes and counted chromosomes in the subsequent Metaphase II eggs. Age-related aneuploidies are due to weakened centromere cohesion. In conclusion, maternal age-associated upsurge in aneuploidy is habitually due to a failure to efficiently substitute cohesion proteins that are lost from chromosomes during aging.

References

Garcia-Cruz, R., Brieno, M. A., Roig, I., Grossmann, M., Velilla, E., Pujol, A., … & Garcia Caldes, M. (2010). Dynamics of cohesin proteins REC8, STAG3, SMC1 β and SMC3 are consistent with a role in sister chromatid cohesion during meiosis in human oocytes. Human reproduction25(9), 2316-2327.

Jessberger, R. (2012). Age‐related aneuploidy through cohesion exhaustion. EMBO reports13(6), 539-546.

“Get 15% discount on your first 3 orders with us”
Use the following coupon
FIRST15

Order Now