What causes multigene families?

Multigene families are believed to have arisen by duplication and variation of a single ancestral gene. Examples of multigene families include those that encode the actins, hemoglobins, immunoglobulins, tubulins, interferons, histones etc.

Which is responsible for evolution of multigene families?

Until around 1990, most multigene families were thought to be subject to concerted evolution, in which all member genes of a family evolve as a unit in concert. Later investigations have shown that most non-rRNA genes including highly conserved histone or ubiquitin genes are subject to this type of evolution.

What is a multigene family quizlet?

– Multigene family is a set of genes descended by duplication. – They are group of similar but not necessarily identical sequences. These sequences are bounded by repeat sequences, The length of the single copy genes varieswidely among plant species.

What is a multigene?

Listen to pronunciation. (MUL-tee-jeen …) A laboratory test in which many genes are studied in a sample of tissue. Multigene tests help find mutations (changes) in certain genes that may increase a person’s risk of a disease such as cancer.

What is an example of a gene family?

Gene family: A group of genes that are related in structure and often in function. The genes in a gene family are descended from an ancestral gene. For example, the hemoglobin genes belong to one gene family that was created by gene duplication and divergence.

How a gene family is produced?

Gene families arose from multiple duplications of an ancestral gene, followed by mutation and divergence. Duplications can occur within a lineage (e.g., humans might have two copies of a gene that is found only once in chimpanzees) or they are the result of speciation.

What is meant by transcriptome?

A transcriptome is the full range of messenger RNA, or mRNA, molecules expressed by an organism. The term “transcriptome” can also be used to describe the array of mRNA transcripts produced in a particular cell or tissue type.

What features characterize gene families?

What features characterize gene families? A group of genes that have related sequences, believed to have been derived from repeated duplication. Eukaryotic protein-coding genes differ from their prokaryotic counterparts in that only eukaryotic genes: contain introns.

What are genomic hotspots quizlet?

the locations that correspond to most genetic diseases, the areas of a genome that most often mutate due to enviromental effects, and the locations that most often correspond with chromosomal breakpoints.

What is highly repetitive DNA?

Repetitive DNA: DNA sequences that are repeated in the genome. These sequences do not code for protein. One class termed highly repetitive DNA consists of short sequences, 5-100 nucleotides, repeated thousands of times in a single stretch and includes satellite DNA.

What is a gene superfamily?

Abstract. Multigene families are defined as groups of genes with sequence homology and related overlapping functions, whereas superfamilies are defined as a group of proteins or genes of common origin with nonoverlapping functions.

How does a gene family arise?

Which is larger a gene family or a multigene family?

Superfamilies are much larger than single multigene families. Superfamilies contain up to hundreds of genes, including multiple multigene families as well as single, individual gene members. The large number of members allows superfamilies to be widely dispersed with some genes clustered and some spread far apart.

What are the four levels of duplication in gene families?

In the formation of gene families, four levels of duplication exist: 1) exon duplication and shuffling, 2) entire gene duplication, 3) multigene family duplication, and 4) whole genome duplication. Exon duplication and shuffling gives rise to variation and new genes.

How are gene families formed over evolutionary time?

Gene families are large units of information and genetic variability. Over evolutionary time, gene families have expanded and contracted with new gene families being formed and some gene families being lost.

How are gene families maintained in high homogeneity?

The process by which gene families maintain high homogeneity is Concerted evolution. Concerted evolution occurs through repeated cycles of unequal crossing over events and repeated cycles of gene transfer and conversion. Unequal crossing over leads to the expansion and contraction of gene families.