Analysis And Application Of Simple Repeat Sequences In Cucurbitaceae

Cucurbitaceae is a family of plants with very high economic value and nutritional value.It can be used as food,oil,protein,medicine and utensils,etc.The abundant variety of shapes exhibited by the Cucurbitaceae family can be used as the main model for gender expression analysis.With the rapid development of DNA molecular marker technology and the application in the field of cucurbitae species,the research topics related to the genetics,breeding and diseases have gradually progressed to the modern molecular field in cucurbitaceae species.In the context of the sequencing of the cucurbit species such as cucumbers,watermelons,etc.,the studies have entered an era of high-throughput information outbreaks in Cucurbitaceae.In order to further develop the genetic information in Cucurbitaceae species,bioinformatics techniques were used to conduct large-scale microsatellite excavation on 6 genomic sequences and 4 EST sequences of 5 cucurbitae species.At the same time,related primers and universal primers were developed.We have developed 2,590,063 complete microsatellite markers and 174,493 pairs of primers in genome of the cucurbitae species.A total of 663,852 microsatellite markers and 60,700 pairs of primers were developed in their EST sequences.At the same time,54 pairs of universal primers were developed.The SSRs' density of the Cucurbitaceae genome is generally higher than that of the control species.Among the Cucurbitaceae genomes,gourd had the highest SSRs density(1723.6 SSRs/Mb),while in the EST sequence,cucumbers had the highest SSRs density(1424.1 SSRs/Mb).Among all types of SSRs in Cucurbitaceae,the hexamer repeat type had the highest specific gravity,which accounted for 50.64% in genome,and a higher proportion in EST sequences,reaching 60.18%.At the same time,it was found that in EST sequences,the specific gravity of the terpolymer repeat type increased significantly.The type of microsatellite based on AT motif has obvious advantages in Cucurbitaceae.In addition to the repeat types of trimers and hexamers,the number of motifs overall tends to decrease as the number of bases in the motif increases,but in the triple and hexamer repeat types,there will be an abrupt Increased exceptions.The GC content of the microsatellite sequence of the Cucurbitaceae species was overall low(around 20%),and the EST sequences was only slightly higher than the GC content of the microsatellite of the genome sequences.Finally,a microsatellite database of Cucurbitaceae was built,which included all the microsatellite markers and their primer sequences developed in this study to facilitate the user's query and use.