scholarly journals The insulin-like growth factor 2 gene and locus in nonmammalian vertebrates: Organizational simplicity with duplication but limited divergence in fish

2018 ◽  
Vol 293 (41) ◽  
pp. 15912-15932 ◽  
Author(s):  
Peter Rotwein
Keyword(s):  
Growth Factor ◽  
Gene Promoters ◽  
Insulin Like Growth Factor ◽  
Protein Coding ◽  
Multiple Gene ◽  
Terrestrial Vertebrates ◽  
Evolutionary Diversification ◽  
Coding Regions ◽  
Prenatal Growth ◽  
Parental Imprinting

The small, secreted peptide, insulin-like growth factor 2 (IGF2), is essential for fetal and prenatal growth in humans and other mammals. Human IGF2 and mouse Igf2 genes are located within a conserved linkage group and are regulated by parental imprinting, with IGF2/Igf2 being expressed from the paternally derived chromosome, and H19 from the maternal chromosome. Here, data retrieved from genomic and gene expression repositories were used to examine the Igf2 gene and locus in 8 terrestrial vertebrates, 11 ray-finned fish, and 1 lobe-finned fish representing >500 million years of evolutionary diversification. The analysis revealed that vertebrate Igf2 genes are simpler than their mammalian counterparts, having fewer exons and lacking multiple gene promoters. Igf2 genes are conserved among these species, especially in protein-coding regions, and IGF2 proteins also are conserved, although less so in fish than in terrestrial vertebrates. The Igf2 locus in terrestrial vertebrates shares additional genes with its mammalian counterparts, including tyrosine hydroxylase (Th), insulin (Ins), mitochondrial ribosomal protein L23 (Mrpl23), and troponin T3, fast skeletal type (Tnnt3), and both Th and Mrpl23 are present in the Igf2 locus in fish. Taken together, these observations support the idea that a recognizable Igf2 was present in the earliest vertebrate ancestors, but that other features developed and diversified in the gene and locus with speciation, especially in mammals. This study also highlights the need for correcting inaccuracies in genome databases to maximize our ability to accurately assess contributions of individual genes and multigene families toward evolution, physiology, and disease.

scholarly journals Similarity and variation in the insulin-like growth factor 2 - H19 locus in primates

2018 ◽  
Vol 50 (6) ◽  
pp. 425-439 ◽  
Author(s):  
Peter Rotwein
Keyword(s):  
Growth Factor ◽  
Primate Species ◽  
Evolutionary Divergence ◽  
Insulin Like Growth Factor ◽  
Distal Enhancer ◽  
Igf2 Gene ◽  
Regulatory Processes ◽  
Prenatal Growth ◽  
Parental Imprinting ◽  
H19 Gene

Insulin-like growth factor 2 (IGF2), a small, secreted protein, is critical for fetal and prenatal growth in humans and other mammals. The IGF2 gene and its mouse homolog comprise part of a conserved linkage group that is regulated by parental imprinting, with IGF2/ Igf2 being expressed from the paternal chromosome, and the adjacent H19 gene from the maternal chromosome. By using information extracted from public genomic and gene expression databases, I have now analyzed this locus in nine nonhuman primate species representing over 60 million years of evolutionary divergence from a common progenitor. Both IGF2 and H19 genes and the entire locus have been conserved among these primates. Each primate IGF2 gene except for gibbon and marmoset is composed of 10 exons and contains five potential promoters, each with distinctive 5′-untranslated exons. Similarly, except for marmoset and mouse lemur, H19 consists of six exons and has two promoters. DNA sequence conservation is high, not only in orthologous exons and promoters, but also in a putative imprinting control region located 5′ to H19 and in multiple potential distal enhancer elements found 3′ to H19. Collectively, these results support the hypothesis that common regulatory processes shaped the IGF2 - H19 locus before the onset of primate speciation more than 85 million years ago. This study also leads to the conclusion that inaccuracies in data presentation in genetic repositories could limit our ability to develop novel insights about roles of individual genes and multigene loci in mammalian physiology and disease.

scholarly journals Parental imprinting of rat insulin-like growth factor II gene promoters is coordinately regulated.

1994 ◽  
Vol 269 (39) ◽  
pp. 23970-23975
Author(s):  
P.V. Pedone ◽  
M.P. Cosma ◽  
P. Ungaro ◽  
V. Colantuoni ◽  
C.B. Bruni ◽  
...  
Keyword(s):  
Growth Factor ◽  
Gene Promoters ◽  
Insulin Like Growth Factor ◽  
Factor Ii ◽  
Parental Imprinting

scholarly journals Identification of a novel transcription unit in the human insulin-like growth factor-II gene

1991 ◽  
Vol 280 (2) ◽  
pp. 439-444 ◽  
Author(s):  
K Ikejiri ◽  
T Wasada ◽  
K Haruki ◽  
N Hizuka ◽  
Y Hirata ◽  
...  
Keyword(s):  
Growth Factor ◽  
Human Insulin ◽  
Sequence Similarity ◽  
Single Copy ◽  
Transcription Unit ◽  
Insulin Like Growth Factor ◽  
Protein Coding ◽  
Consensus Sequences ◽  
Genomic Location ◽  
Factor Ii

The human insulin-like growth factor-II (hIGF-II) gene has until now been thought to be composed of eight exons, including three independent leader exons. In the present study two additional exons, one leader exon and one alternatively used ordinate exon, have been newly identified. They were abundantly expressed in human histiocytoma tissue, generating mRNA species of about 5.0 kb in length. The new leader exon shows significant sequence similarity with the rE1 exon, previously reported to be transcribed only in the rat, and is mapped at nearly the same genomic location as in the rat. On the other hand, sequence similarity with another exon in the corresponding region of the rat genome was also found. It was, however, obvious that the rat sequence would not work as an active exon, since both splice acceptor and donor sites were deviated considerably from the consensus sequences. It has thus become apparent that the complex transcription unit of a single-copy hIGF-II gene comprises at least 10 exons, including four leader exons, one alternative exon and three common protein-coding exons.

scholarly journals Parental imprinting: potentially active chromatin of the repressed maternal allele of the mouse insulin-like growth factor II (Igf2) gene.

1992 ◽  
Vol 6 (10) ◽  
pp. 1843-1856 ◽  
Author(s):  
H Sasaki ◽  
P A Jones ◽  
J R Chaillet ◽  
A C Ferguson-Smith ◽  
S C Barton ◽  
...  
Keyword(s):  
Growth Factor ◽  
Insulin Like Growth Factor ◽  
Maternal Allele ◽  
Active Chromatin ◽  
Igf2 Gene ◽  
Factor Ii ◽  
Parental Imprinting

scholarly journals Concordant Loss of Imprinting of the Human Insulin-like Growth Factor II Gene Promoters in Cancer

1995 ◽  
Vol 270 (47) ◽  
pp. 27983-27986 ◽  
Author(s):  
Shili Zhan ◽  
David Shapiro ◽  
Shixing Zhan ◽  
Lijuan Zhang ◽  
Steven Hirschfeld ◽  
...  
Keyword(s):  
Growth Factor ◽  
Human Insulin ◽  
Gene Promoters ◽  
Insulin Like Growth Factor ◽  
Loss Of Imprinting ◽  
Factor Ii

scholarly journals Morpho-Phylo Taxonomy of Novel Dothideomycetous Fungi Associated With Dead Woody Twigs in Yunnan Province, China

2021 ◽  
Vol 12 ◽  
Author(s):  
Peter E. Mortimer ◽  
Rajesh Jeewon ◽  
Jian-Chu Xu ◽  
Saisamorn Lumyong ◽  
Dhanushka N. Wanasinghe
Keyword(s):  
Yunnan Province ◽  
Phylogenetic Analyses ◽  
Protein Coding ◽  
Research Attention ◽  
Multiple Gene ◽  
Asexual Morph ◽  
Coding Regions ◽  
Extant Species ◽  
Ocular Chamber ◽  
Taxonomic Novelties

Within the field of mycology, macrofungi have been relatively well-studied when compared to microfungi. However, the diversity and distribution of microfungi inhabiting woody material have not received the same degree of research attention, especially in relatively unexplored regions, such as Yunnan Province, China. To help address this knowledge gap, we collected and examined fungal specimens from different plants at various locations across Yunnan Province. Our investigation led to the discovery of four species that are clearly distinct from extant ones. These taxonomic novelties were recognized based on morphological comparisons coupled with phylogenetic analyses of multiple gene sequences (non-translated loci and protein-coding regions). The monotypic genus Neoheleiosa gen. nov. (type: N. lincangensis) is introduced in Monoblastiaceae (Monoblastiales) for a woody-based saprobic ascomycete that possesses globose to subglobose or obpyriform ascomata with centric or eccentric, papillate ostioles, an ascomatal wall with thin-walled cells of textura globulosa, cylindric, pedicellate asci with an ocular chamber, and 1-septate, brown, guttulate, longitudinally striated, bicellular ascospores. Neoheleiosa has a close phylogenetic affinity to Heleiosa, nevertheless, it is morphologically dissimilar by its peridium cells and ornamented ascospores. Acrocalymma hongheense and A. yuxiense are described and illustrated as new species in Acrocalymmaceae. Acrocalymma hongheense is introduced with sexual and asexual (coelomycetous) features. The sexual morph is characterized by globose to subglobose, ostiolate ascomata, a peridium with textura angularis cells, cylindric-clavate asci with a furcate to truncate pedicel and an ocular chamber, hyaline, fusiform, 1-septate ascospores which are surrounded by a thick, distinct sheath, and the asexual morph is featured by pycnidial conidiomata, subcylindrical, hyaline, smooth, annelledic, conidiogenous cells, hyaline, guttulate, subcylindrical, aseptate conidia with mucoid ooze at the apex and with a rounded hilum at the base. Acrocalymma yuxiense is phylogenetically distinct from other extant species of Acrocalymma and differs from other taxa in Acrocalymma in having conidia with three vertical eusepta. Magnibotryascoma kunmingense sp. nov. is accommodated in Teichosporaceae based on its coelomycetous asexual morph which is characterized by pycnidial, globose to subglobose, papillate conidiomata, enteroblastic, annelledic, discrete, cylindrical to oblong, hyaline conidiogenous cells arising from the inner layer of pycnidium wall, subglobose, oval, guttulate, pale brown and unicelled conidia.

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