Inter Simple Sequence Repeat (ISSR) Markers for Assessment of Genetic Polymorphism and Phylogenetic Relationships of the Silkworm Bombyx mori L.

2014 ◽  
Vol 4 (6) ◽  
pp. 897-905 ◽  
Author(s):  
Shivakumar Bakkappa
Genome ◽  
2005 ◽  
Vol 48 (5) ◽  
pp. 802-810 ◽  
Author(s):  
Muwang Li ◽  
Li Shen ◽  
Anying Xu ◽  
Xuexia Miao ◽  
Chengxiang Hou ◽  
...  

To determine genetic relationships among strains of silkworm, Bombyx mori L., 31 strains with different origins, number of generations per year, number of molts per generation, and morphological characters were studied using simple sequence repeat (SSR) markers. Twenty-six primer pairs flanking microsatellite sequences in the silkworm genome were assayed. All were polymorphic and unambiguously separated silkworm strains from each other. A total of 188 alleles were detected with a mean value of 7.2 alleles/locus (range 2–17). The average heterozygosity value for each SSR locus ranged from 0 to 0.60, and the highest one was 0.96 (Fl0516 in 4013). The mean polymorphism index content (PIC) was 0.66 (range 0.12–0.89). Unweighted pair group method with arithmetic means (UPGMA) cluster analysis of Nei's genetic distance grouped silkworm strains based on their origin. Seven major ecotypic silkworm groups were analyzed. Principal components analysis (PCA) for SSR data support their UPGMA clustering. The results indicated that SSR markers are an efficient tool for fingerprinting cultivars and conducting genetic-diversity studies in the silkworm.Key words: silkworm, Bombyx mori L., microsatellites, simple sequence repeat (SSR), genetic diversity.


2008 ◽  
Vol 35 (5) ◽  
pp. 291-297 ◽  
Author(s):  
Dhanikachalam Velu ◽  
Kangayam M. Ponnuvel ◽  
Murugiah Muthulakshmi ◽  
Randhir K. Sinha ◽  
Syed M.H. Qadri

Genome ◽  
2005 ◽  
Vol 48 (3) ◽  
pp. 355-366 ◽  
Author(s):  
S Nageswara Rao ◽  
B Surendra Nath ◽  
B Saratchandra

This study is the first report on the genetic characterization and relationships among different microsporidia infecting the silkworm, Bombyx mori, using inter simple sequence repeat PCR (ISSR-PCR) analysis. Six different microsporidians were distinguished through molecular DNA typing using ISSR-PCR. Thus, ISSR-PCR analysis can be a powerful tool to detect polymorphisms and identify microsporidians, which are difficult to study with microscopy because of their extremely small size. Of the 100 ISSR primers tested, only 28 primers had reproducibility and high polymorphism (93%). A total of 24 ISSR primers produced 55 unique genetic markers, which could be used to differentiate the microsporidians from each other. Among the 28 SSRs tested, the most abundant were (CA)n, (GA)n, and (GT)n repeats. The degree of band sharing was used to evaluate genetic similarity between different microsporidian isolates and to construct a phylogenetic tree using Jaccard's similarity coefficient. The results indicate that the DNA profiles based on ISSR markers can be used as diagnostic tools to identify different microsporidia with considerable accuracy. In addition, the small subunit ribosomal RNA (SSU-rRNA) sequence gene was amplified, cloned, and sequenced from each of the 6 microsporidian isolates. These sequences were compared with 20 other microsporidian SSU-rRNA sequences to develop a phylogenetic tree for the microsporidia isolated from the silkworms. This method was found to be useful in establishing the phylogenetic relationships among the different microsporidians isolated from silkworms. Of the 6 microsporidian isolates, NIK-1s revealed an SSU-rRNA gene sequence similar to Nosema bombycis, indicating that NIK-1s is similar to N. bombycis; the remaining 5 isolates, which differed from each other and from N. bombycis, were considered to be different variants belonging to the species N. bombycis.Key words: microsporidia, Nosema, silkworm, Bombyx mori, inter simple sequence repeat PCR, small subunit rRNA, phylogeny.


2010 ◽  
Vol 39 (1) ◽  
pp. 119-122 ◽  
Author(s):  
Mahmudul Islam Nazrul ◽  
Fan Xiao Lin ◽  
Bian Yin-Bing

Among ten slow-growing protoclones of Agaricus bisporus (J. Lge) Imbach, all appressed colonies showed slower growth rate and spawn run, and inability to produce fruiting bodies in substrate. Seven of 40 inter-simple sequence repeat (ISSR) primers amplified 78 reproducible fragments, 48.93% were polymorphic, each producing 7 to 16 bands ranging from 0.10 to 2.10 kbp, sufficient to differentiate the protoclones from each other. Appressed protoclones were homoallelic at a number of loci that were heteroallelic in the parent, suggesting that they represented rare homokaryons. Thus, using morphological characters along with ISSR, polymorphisms could be useful for quick, easy, and accurate in distinguishing homo- and heterokaryotic isolates. Key words: Agaricus bisporus (J. Lge) Imbach; Homokaryon; ISSR; Protoclone DOI: 10.3329/bjb.v39i1.5537Bangladesh J. Bot. 39(1): 119-122, 2010 (June)


2015 ◽  
Vol 22 (2) ◽  
pp. 67-75 ◽  
Author(s):  
Leila Samiei ◽  
Mahnaz Kiani ◽  
Homa Zarghami ◽  
Farshid Memariani ◽  
Mohammad Reza Joharchi

In this study genetic diversity and interspecific relationships of 11 Allium L. species from Khorassan province of Iran including 32 accessions were investigated by inter simple sequence repeat (ISSR) markers. Nine ISSR primers produced a total of 80 polymorphic markers and revealed high polymorphism among the studied species. The average gene diversity, effective number of alleles and Shannon’s information index were 0.2, 1.28 and 0.3, respectively. Allium kuhsorkhense exhibited the greatest level of variation (He: 0.18), whereas A. stipitatum demonstrated the lowest level of variability (He: 0.05). UPGMA (Unweighted Pair Group Method with Arithmetic mean) analysis showed that Allium accessions have a similarity range of 0.60 to 0.95. Allium scapriscapum composed the most distant group in the dendrogram. The clustered groups of Allium species clearly reflect the recent taxonomic concept of the genus at the subgenus and section levels. The present study showed that the ISSR technique is an effective molecular approach for analyzing genetic diversity and relationship in Allium species.Bangladesh J. Plant Taxon. 22(2): 67-75, 2015 (December)


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