Mendelian Genetics Terms PDF

[[Mendelian Genetics Terms and Definitions]](http://www.barnardgenetutor.com/table_of_contents_htm.html) Lecture 1 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -...

[[Mendelian Genetics Terms and Definitions]](http://www.barnardgenetutor.com/table_of_contents_htm.html) Lecture 1 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Lecture 2 - - - - - - Symbol Term Definition --------------------------- ---------------------------------- ------------------------------------------------ Unaffected male Do not express trait in this particular male  Unaffected female Do not express trait in this particular female Affected male Express trait in this particular male  Affected female Express trait in this particular female Mating  Progeny Deceased D. 0000 Date of death  Unspecified sex Parents closely related by blood  Adoption Siblings Numbers: I, II, III, etc. Roman numerals Numbered generations Numbers: 1, 2, 3, etc.S Arabic Numbers Individuals in a generation - - - - - - Lecture 3 Gene product- (1) the functional molecule encoded. Usually we think of protein products, sometimes RNA depending on the type of gene Gene expression- (1 /2) A gene's functional product is produced. (2/2) A gene is transcribed and translated.\ Allele-\ Substitution- A single nucleotide change Indel- A short insertion or deletion (shortest possible indel = 1 nucleotide) Missense mutation- A mutation leading to a single amino acid change Nonsense mutation- Mutation of an amino-acid encoding codon to a stop codon Frameshift mutation- Mutation (insertion or deletion) that alters reading frame and thus the encoded downstream amino acids Coding mutation- Regulatory mutation- Can affect the activity of a gene's promoter, enhancer, splicing, mRNA stability, etc: anything that alters the expression of the gene product.\ Loss of function- (1/ 2) Reduces or eliminates production of functional product. (2/2) Alleles that decrease or eliminate functional activity Null allele or amorphic allele- Alleles whose product have no functional activity\ Partial loss of function- hypomorphic allele- less formed allele\ conditional allele- (1/ 2) Alleles with loss of function activity only under some circumstances. (2/2) Temperature sensative allele are a common type of this naturally-occurring allele Temperature sensitive allele- (1/ 2) A common type of naturally occuring conditional allele. (2/2) Encode a variant enzyme that is functional only at certain temperatures.\ Gain of function allele- (1/ 2) Alleles that increase or otherwise change the functional activity of a gene product. (2/2) When an allele encodes a product with more function or a new function compared to the wild-type product. Gain of function- Product has new or higher activity, or acts at a new time place Hypermorphic- Alleles whose product has increased functional activity Neomorphic- (1/3) Alleles whose product has a new functional activity. (2/3) Alleles whose new product is encoded with variant functional activity. (3/3) Alleles whose same product is encoded but the product is expressed ina new place/time. \- Time Refers to\ Dominant negative allele- When an allele encodes a product whose function interferes with the function of the wild-type product\ Haplosufficiency- (1/ 2) Genes for which loss of function alleles are recessive to functional alleles. (2/2) A single \[allele\] of the functional allele produces sufficient activity for a wild type phenotype.\ Haploinsufficiency- (1/3) Genese for which the loss of function alleles are dominant to functional alleles. (2/3) The two copies of a functional allele are necessary to produce enough gene product activity for a wild-type phenotype. (3/3) A gene requires two wild-type (functional) alleles to produce the wild-type phenotype.\ Co-dominance- When the phenotypes associated with both alleles show in the heterozygote.\ Incomplete dominance- When the phenotype of the heterozygotes is intermediate between the phenotypes of the two heterozygotes.\ Lethal mutation- (1 /2) Lead to modified Mendelian ratios in crosses. (2/ )\ Pleiotropy- When an allele (or gene) produces multiple different phenotypes.\ Allelic series\ gene -- Environment interaction- (1/ 2) Environment affect the phenotypic ratio of many traits! Phenotypic plasticity- is **reproducible** phenotype variation in response to variation in **environmental** conditions. - Polyphenism expressivity- A type of plasticity in which 2 or more **distinct body forms** are produced by different developmental programs under different environmental conditions.\ Penetrance- Proportion of individuals that show a phenotype associated with a particular genotype. Incomplete penetrance- Many alleles show incomplete penetrance. Meaning that not everyone who carries this allele develops this phenotype. Expressivity- The degree to which a particular genotype is expressed in the phenotype of an individual. Many alleles show variable expressivity. The degree to which a particular genotype is expressed is variable.\ wild type Lecture 4- Chapter 4 and 14 Reverse genetics- (1/ 4) Genetic analysis that begins with a gene sequence, which is used to identify or introduce mutant alleles and subsequently to identify and evaluate the resulting mutant phenotype. It is the complementary approach to forward genetics. (Textbook glossary G-16) (2/ 4) Mode of study where a researcher starts with a gene of interest, generates mutation(s) in that gene, and analysizes mutants to understand the role of that gene. (3/4) Genetic analysis that is typically used when researchers already have a hypothesis about which gene(s) regulate their trait of interest. (4/4) Also called a candidate approach, would be used for example, if researchers might hypothesize that a gene regulates a trait based on: - - - CRISPR/Cas9- (1/ 4) a bacterial immune defense system (2/4) adapted as a technology for genome editing, or a way to make defined DNA sequences change (3/ 4) a tool for making new alleles (4/4) Complex of the Cas9 protein with tracrRNA and crRNA that acts to target invading nucleic acids in *Staphylococcus*. This system has been modified for use in gene editing. (Textbook G-5) CRISPR- *C*lustered *R*egularly *I*nterspaced *S*hort *P*alindromic *R*epeats. Transcribed repetitive sequence that is processed into unique crRNAs acting in a bacterial or archael immune system. [[Forward genetic screen:]](https://courseworks2.columbia.edu/courses/200342/files/folder/Slides?preview=21674576) Slide 15 Purpose Mutagenesis Mutagens Screening for recessive mutations Screening for dominant mutations Lecture 5- Genetic interactions part 1 Genetic interaction Epistasis- (1/ 4) Is detected as modified phenotype ratios in crosses (2/ 4) phenotype ratios in crosses that are not akin to phenotype ratios in Mandelian crosses such as a 9:3:4 recessive \_\_\_\_\_\_ phenotypic ratio instead of a 9:3:3:1 ratio for a dihybrid cross, 12:3:1 dominant \_\_\_\_\_\_, and 9:7 \_\_\_\_\_ with duplicate genes  (3/4) a type of genetic interaction in which allele(s) of one genemask the phenotypic effect of a second gene. (Lecture 5, Slide 7) (4 /4) In an anabolic/biosynthetic or catabolic/metabolic pathway, upstream genes are \_\_\_\_ to downstream genes. Epistatic interaction- (1/ 2) A group of specific patterns of gene interaction in which an allele of one gene modifies or prevents the expression of alleles of another gene. (Textbook page G-6; also known as epistasis.) (2/2) Observation of a genetic interaction indicates that genes act in the same pathway. Genetic interactions can sometimes also be used to determine the order in which genes act in a pathway. This describes the use of studying genetic interaction to identify \_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_. (Lecture 5, Slide 7) Recessive epistasis- (1/ 5) Recessive alleles at one locus mask the phenotypic expression of other gene locus. [[Epistasis types - dominant, recessive, double dominant, dominant recessive epistasis]](https://www.youtube.com/watch?v=ekJrgMf-kmY) (2/5) The recessive allele at one position in the genome sequence hides the observable expression of an allele at another locus. So if an individual is \_\_\_\_\_ for \_\_\_\_\_ and at \_\_\_\_\_ this means that \_\_\_\_ would mask the expression of an allele at a different locus. (3/ 5) 9:3:4 ratio (4/ 5) A characteristic ratio of phenotypes produced by the interaction of two genes that control a trait in which a dominant allele of one gene masks or reduces the expression of alleles of a second gene. (Textbook page G-15) Dominant epistasis- 1/ 7) Dominant alleles at one locus mask the phenotypic expression of other gene locus. [[Epistasis types - dominant, recessive, double dominant, dominant recessive epistasis]](https://www.youtube.com/watch?v=ekJrgMf-kmY) (2/7) 'A' masks the expression of 'B' 'A' is epistatic gene of 'B.' A can express itself only in the presence of 'B' or b allele. Therefore, it is called... (3/7) The dominant allele at one position in the genome sequence hides the observable expression of an allele at another locus. So if an individual is \_\_\_\_\_ for \_\_\_\_\_ and at \_\_\_\_\_ this means that \_\_\_\_ would mask the expression of an allele at a different locus. (4/ 7) 'B' expresses only when 'aa' is present. This is called.... (5/ 7) 12:3:1 ratio (6/ 7) A characteristic ratio of phenotypes produced by the interaction of two genes that control a trait in which a dominant allele of one gene masks or reduces the expression of alleles of a second gene. (Textbook page G-6) Complementary gene action (mutual recessive epistasis) - (1/ 2)- Both genes are required for the correct phenotype, this \_\_\_\_\_ interaction is called \_\_\_\_\_\_ \_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_. (2/2) Observed when two genes act in the same pathway, but they have the same loss-of-function phenotype Redundancy (mutant dominant epistasis) - (1/ 2) Observed when multiple genes perform the same function The image shown is an example of... Modifier gene - (1/ 4) Allele(s) of one gene modify the phenotypic effect of alleles of a second gene (2/ 4) Allele(s) of one gene strengthen, weaken or otherwise change the phenotypic effect of alleles of a second gene (3/ 4) Many \_\_\_\_ alleles do not produce a phenotype on their own, in a wild-type background Complementation, Complementation group - Recessive alleles of the same gene form a \_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_. genetic complementation \(1) The observation of a wild-type phenotype in an organism or cell containing two different mutations. (2) The cross of two pure-breeding mutants that yields progeny that are exclusively wild type. (Textbook G-8) genetic complementation analysis The experimental pairwise comparison of genetic mutants designed to determine whether mutants complement one another by producing wild types. (Textbook G-8) Lecture 6- Genetic interactions part 2 Lecture 7- Linkage Recombination linkage sex-linked trait autosomal trait allelic phases, Cis and trans hemizygous recombination parental, or non-recombinant non-parental, or recombinant test cross genetic map centimorgan, map unit Lecture 8- Mapping Part 1 VNTR SNP Polymerase chain reaction (PCR), including major steps Gel electrophoresis, Including how to read gel results Genetic linkage mapping, general approach and interpretation of results lod, including how to calculate Maximum lod Lecture 9- Mapping, part 2. Reading: section 5.5. Genome-wide association study (GWAS) Linkage disequilibrium Manhattan plot (interpretation)