کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5909211 1570171 2015 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Elucidating evolutionary features and functional implications of orphan genes in Leishmania major
ترجمه فارسی عنوان
توضیح ویژگی های تکاملی و پیامدهای کاربردی ژنهای یتیم در لیشمانیا بزرگ
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک بوم شناسی، تکامل، رفتار و سامانه شناسی
چکیده انگلیسی


- Along with gene age several genomic and proteomic features could modulate evolutionary rate of orphan genes.
- Prevalent structural disorder in orphan genes is crucial for their faster evolution and functions.
- Longer protein length is an interesting feature of orphan genes in L. major.
- Orphan genes of L. major contain several interaction and trafficking motifs essential for host-parasite interactions.

Orphan genes are protein coding genes that lack recognizable homologs in other organisms. These genes were reported to comprise a considerable fraction of coding regions in all sequenced genomes and thought to be allied with organism's lineage-specific traits. However, their evolutionary persistence and functional significance still remain elusive. Due to lack of homologs with the host genome and for their probable lineage-specific functional roles, orphan gene product of pathogenic protozoan might be considered as the possible therapeutic targets. Leishmania major is an important parasitic protozoan of the genus Leishmania that is associated with the disease cutaneous leishmaniasis. Therefore, evolutionary and functional characterization of orphan genes in this organism may help in understanding the factors prevailing pathogen evolution and parasitic adaptation. In this study, we systematically identified orphan genes of L. major and employed several in silico analyses for understanding their evolutionary and functional attributes. To trace the signatures of molecular evolution, we compared their evolutionary rate with non-orphan genes. In agreement with prior observations, here we noticed that orphan genes evolve at a higher rate as compared to non-orphan genes. Lower sequence conservation of orphan genes was previously attributed solely due to their younger gene age. However, here we observed that together with gene age, a number of genomic (like expression level, GC content, variation in codon usage) and proteomic factors (like protein length, intrinsic disorder content, hydropathicity) could independently modulate their evolutionary rate. We considered the interplay of all these factors and analyzed their relative contribution on protein evolutionary rate by regression analysis. On the functional level, we observed that orphan genes are associated with regulatory, growth factor and transport related processes. Moreover, these genes were found to be enriched with various types of interaction and trafficking motifs, implying their possible involvement in host-parasite interactions. Thus, our comprehensive analysis of L. major orphan genes provided evidence for their extensive roles in host-pathogen interactions and virulence.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Infection, Genetics and Evolution - Volume 32, June 2015, Pages 330-337
نویسندگان
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