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11

...would then be his offspring at risk? Why? No. Generally speaking, fathers do not pass on their mtDNA (Mitochondrial DNA). Why? Because the mitochondria present in oocytes (egg cell) is the mother's, as every oocyte directly inherits the mother's mitochondria when they are made in the reproductive organs. The mitochondria that the sperm from the father ...


7

I would suggest searching the name in any trusted genetics database such as NCBI's GenBank (http://www.ncbi.nlm.nih.gov/genbank/). You can just Google search it, but it may take a little longer to find useful information that way. I hope this helps and good luck with your research, CDB


6

Alleles are basically subtypes of a gene. At the time of Mendel, the molecular nature of inheritance was not known so the original definition of gene refers to "some" inheritable molecular entity inside the organism that is responsible for a trait. Alleles are different "flavours" of a given gene. For example there is a gene for flower colour, there can be ...


6

You are absolutely correct that many traits are not "digital", but "analog". In genetics, these are usually called quantitative traits. Such traits generally do not follow Mendel's laws of inheritance, but are said to have "complex inheritance". Most traits (phenotypes) in biology at the level of whole organisms probably have complex genetics; height is a ...


5

Was getting long in the comments. In light of your comments, you might be interested in Gene-set enrichment analysis (GSEA). You can do a GSEA using your set, the other one coming from reference databases such as MSigDB (see here). You can categorize your list by gene families using this technique for example. You can get an idea of what cellular process ...


5

TL;DR: Ubiquitin. Occasional occurrence of paternal inheritance of mtDNA has been suggested in mammals including humans. Clearly, spermatozoa have mitochondria; they make the energy needed for motility. Paternal mitochondrial DNA (mtDNA) does enter oocytes. It is a persisting fallacy that only maternal mtDNA is present in humans because only oocyte ...


5

Take a look at this schematic of a mature mRNA. [source] The coding region (ie the part that is translated) is between the start and stop codons, but the 5' and 3' untranslated regions (UTRs) are also transcribed by RNA polymerase; these are part of the first and last exons, respectively. The transcription start site is labelled right in front of the 5' ...


5

You mix up translation and transcription. Transcription creates mRNA from DNA template. Transcription also includes splicing, that is excision of introns so that mature mRNA contains only exons. In your example it goes like that: DNA (chromosome): ---A----B--...--Dstop---E--- premature mRNA: A----B---...---Dstop--E---polyA mature mRNA: AB..DstopE-polyA ...


5

Most promoter elements are not a part of the mRNA sequence. They are upstream (towards 5') of the transcription start site. However, a certain class of promoters called downstream promoter elements (DPE) can overlap with the geneic region. These elements have been reported to lie at 29-33bp upstream of the transcription start site and widely employed, in ...


5

So the term allele is a broad one, and simply refers to the different versions of any piece of DNA in circulation in the gene pool - it doesn't need to refer to a gene. I can talk about the alleles at a random place in the genome. But if we proceed with your question and ask - 'do nonsense mutations within coding genes also lead to the creation of different ...


4

Physical and genetic interactions are described in the help wiki, accessed via the top menu bar on the page you linked to. Physical interactions refer to experiments where the gene product (protein) has been shown to physically interact with another protein, such as by co-immunoprecipitation, fluorescent staining, yeast two-hybrid system, etc. Genetic ...


4

TL;DR: Chymosin is similar to pepsin and I couldn't find any evidence of functional/expressed chymosin gene in human genome. It seems like a common misconception that chymosin is functional in humans. Already in 1940s it has been shown that rennin (aka chymosin) is absent from "gastric juice" in adult humans. Genetically there is only pseudo-gene for ...


4

According to this website, it is a mnemonic for "lambda excision". I have also found this usage in scientific literature (Harami et al., 2013). However, neither of these sources reference anything and I cannot find any defining paper. Almost all papers simply refer to it as lexA. As far as I can find (it's difficult to dig up these old papers), this is how ...


4

I'd go with Lambda Excision A. Terms like lex or rec often stand for what'd be termed a mnemonic, where for example rec may stand for recombination, or umu for UV mutator. The naming conventions can be difficult. Edit: A 1981 study by Roger Brent and Mark Ptashne notes some data from initial studies that showed the lexA repressor downregulated a number of ...


4

There is nothing intrinsic to DNA methylation itself that requires it to repress transcription. Simply, it affects sequence recognition by proteins. CpG methylation can prevent transcription factor binding and/or recruit proteins that inhibit transcription, either competitively or through chromatin condensation. This is why it's generally associated with ...


4

So, the very first map of the human genome was of a few pooled samples with a single nucleotide called at each position. This is basically okay, though, because humans are 99.9 (with possibly a few more 9s) % similar to one another. So you can get a lot of broadly-applicable information out of a single individual's DNA. Further genome-mapping efforts ...


4

Little harm comes from ABO incompatibility (that would have been a major problem with reproduction.) Rh incompatibility is more dangerous, though. If a fetus is Rh+ and the mother is Rh-, when there is mixing of maternal-fetal blood (at birth, but sometimes before that), the mother will form antibodies to the blood cell surface antigen. It doesn't usually ...


3

There is nothing called the 3' to 5' strand. Both strands are have the same polarity but the DNA helix is anti-parallel. Both the strands contain approximately equal number of genes. Sometimes the transcription from both the strands can overlap, leading to production of antisense-transcripts. So RNA polymerase will read the other strand from its 3' to 5'.


3

Both strands have a 5' and 3' end. Some genes will be on one strand and some on the other. The coding sequence will always be 5' to 3', but RNA polymerase reads the template 3' to 5' to polymerize mRNA.


3

It depends; what species are the genes from? Some organisms have extensively annotated genomes, and actively curated species-specific databases, while other species may not even have a reference genome sequence available. By itself, a priori, if you were lucky, about all you list would tell you was how to spell the names of those genes--if you're lucky. But ...


3

If the Cold Spring Harbor Laboratory is considered a reputable source (it should be), you can check out their Defining the gene page which has an overview of the beads-on-a-string theory, and how it was disproved by Seymour Benzer. You could also try to find Benzer's original paper, although it doesnt seem to be available online. Related and possibly ...


3

Can't ORFS be of any size? I think the point being made is that in a random sequence of 64 amino acids, on average 3 out of 64 should be stop codons, because there are three possible nucleotide sequences for stop codons (UAA, UAG, UGA). ORFs could theoretically be any size but the longer the sequence the more likely you are to come across a stop codon ...


3

Both genes and alleles are sequences of DNA. A gene will code for a trait, say hair colour, while an allele will be the variants of that gene (say the alleles coding for blonde, brown, black, and red hair). It's almost like cookbooks: two cookbooks (the DNA) might have a recipe (gene) for bread but they use slightly different instructions (alleles) ...


3

First of all you need to clarify what exactly is the output that needs to be regulated. We often say regulation of expression of a gene but what expression ultimately leads to is the activity of the gene (whatever it might be: enzyme based catalysis, cytoskeletal rearrangement, response to an extracellular signal). Activity of course depends on the ...


2

Let's go through the possible answers. Which of the following could be predicted? Not (1), because we don't know whether selection favors or disfavors the recessive alleles. Not (2) for the same reason. Not (4) by definition. Not (5) because recessive alleles don't magically become dominant. This leaves us with (3), which also seems correct: not only do we ...


2

Assuming each gene symbol represents a unique gene or protein (this may not be true; see for gene name aliases in e.g. NCBI Entrez gene) you can get a lot of information programmatically. Below is an example using R and Bioconductor resources. Define your list of genes: # list of gene symbols, here we focus on one. > genes <- "KRAS" Load the ...


2

Also try putting the list through Reactome or String DB to see if you see mapping to certain pathways. http://string-db.org/ You can also put lists through ConceptGen to carry out ontology based analyses http://portal.ncibi.org/gateway/conceptgen.html


2

Non-disjunction and trisomy 13. Why can't this be 1st meiotic division non-disjunction as well? It absolutely can be 1st meiotic division non-disjunction as well. Patau syndrome can occur as a result of either meiotic non-disjunction event, and furthermore a mosaic form of the disorder can occur after mitotic non-disjunction. Non-disjunction generally....


2

These are not gene ids, but groups of orthologous genes -- try to search for the ids on Google, I can find this page http://cegg.unige.ch/orthodb6/fasta.fasta?ogs=EOG6STSR2&swaptree= and thus you should be able to download the sequences and ids from OrthoDB. Note that, strictly speaking, the are no Ensembl ids for Drosophila, only FlyBase ids that are ...


2

Upstream means towards 5' direction from the reference point (conversely for downstream). Reference point can be a single position such as transcription start site (TSS) or a bigger segment such as a gene. When we say upstream of a gene, it means some region of DNA that is towards 5' direction from the TSS of the reference gene. Downstream of a gene refers ...



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