- #1
Beth N
- 41
- 4
- TL;DR Summary
- I am a college student trying to interpret a biology research paper. The paper is studying the link between mitochondrial gene mutation and changes in gut microbiota composition, using the mice model.
My question is all in the context of this paper. I have problems understanding a definition and a method.
Sina, C. et al. Mitochondrial gene polymorphism is associated with gut microbial communities in mice.
Sci. Rep. 7, 1–9 (2017).
This is a segment of the introduction: "
Since common inbred mouse strains demonstrate unique mitochondrial
genomes
and the mitochondria are strictly maternally inherited, we systematically generated conplastic
strains carrying mostly single mutations in mtDNA with a C57BL/6J nuclear background by repeatedly back
crossing
female mitochondrial-donor strains with male C57BL/6J mice over 12 generations. This unique
resource allowed us to investigate the impact of defined mtDNA mutations on gut microbiota composition in
the absence of confounding variation in the nuclear genome."
I don't understand the method by which they generate " complastic mouse strains" and "backcrossing".
Does backcrossing mean making a breed between an offspring and its parents or another indiividivual with the same genotype as its parent?
And does backcrossing the same thing as testcrossing?
What I understand:
- The purpose of backcrossing is to generate mice strains that only differ in their mitochondrial gene, but not their nucleic gene, so that any difference in the gut microbiota composition is not confounded by difference in the nucleic genes of the mice.
What I don't understand:
I think I'm thinking about how they actually carry out the procedure completely wrong :(. Here's what I've got:
Parents: Male C57BL/6J x Female with same nucleic gene but mutated mitochondrial gene
Generation F1: An offspring male C57BL/6J (same nucleic gene as its father) * any female offspring (<-- could it be a female offspring, or a female unrealted mouse with a different mitochondiral mutation?)
Generation F2: An offspring male C57BL/6J * any female offspring
Repeat for 12 generations.
Any clarifiication would be greatly appreciated!
Sina, C. et al. Mitochondrial gene polymorphism is associated with gut microbial communities in mice.
Sci. Rep. 7, 1–9 (2017).
This is a segment of the introduction: "
Since common inbred mouse strains demonstrate unique mitochondrial
genomes
and the mitochondria are strictly maternally inherited, we systematically generated conplastic
strains carrying mostly single mutations in mtDNA with a C57BL/6J nuclear background by repeatedly back
crossing
female mitochondrial-donor strains with male C57BL/6J mice over 12 generations. This unique
resource allowed us to investigate the impact of defined mtDNA mutations on gut microbiota composition in
the absence of confounding variation in the nuclear genome."
I don't understand the method by which they generate " complastic mouse strains" and "backcrossing".
Does backcrossing mean making a breed between an offspring and its parents or another indiividivual with the same genotype as its parent?
And does backcrossing the same thing as testcrossing?
What I understand:
- The purpose of backcrossing is to generate mice strains that only differ in their mitochondrial gene, but not their nucleic gene, so that any difference in the gut microbiota composition is not confounded by difference in the nucleic genes of the mice.
What I don't understand:
I think I'm thinking about how they actually carry out the procedure completely wrong :(. Here's what I've got:
Parents: Male C57BL/6J x Female with same nucleic gene but mutated mitochondrial gene
Generation F1: An offspring male C57BL/6J (same nucleic gene as its father) * any female offspring (<-- could it be a female offspring, or a female unrealted mouse with a different mitochondiral mutation?)
Generation F2: An offspring male C57BL/6J * any female offspring
Repeat for 12 generations.
Any clarifiication would be greatly appreciated!