Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Sivas Cumhuriyet Üniversitesi, Fen Bilimleri Enstitüsü, Moleküler Biyoloji ve Genetik, Türkiye
Tezin Onay Tarihi: 2019
Tezin Dili: İngilizce
Öğrenci: MELİSSA ŞAFAK ÇELEBİ
Asıl Danışman (Eş Danışmanlı Tezler İçin): Ertan Mahir Korkmaz
Eş Danışman: Robert Paxton
Özet:
Honey bees are very important in terms of the economy and our nutritional requirements. In addition to honey bees, many wild bees (e.g. Bombus spp.) are also important for pollination and their decreasing numbers are another cause of concern where it occurs across the world. One of the most important emerging infectious diseases (EIDs), not only in Apis mellifera but also in Bombus terrestris, is deformed wing virus (DWV), transmitted by the ectoparasitic mite Varroa destructor. DWV is currently found as two prevalent genotypes: DWV genotype A (DWV-A) and DWV genotype B (DWV-B), also known as Varroa destructor virus-1. Recombinants between DWV-A and DWV-B have also been detected in field-collected bees. Apis mellifera is a very important commercial pollinator so there are many studies on the effects of DWV on it. Indeed, DWV and its parasitic mite vector, Varroa destructor, are believed to be important causes for honey bee loss and colony failure. However, although other bee species (e.g. Bombus spp.) play a significant role in pollination, research on the impact of viruses on them, including DWV, is limited. When two genotypes of a virus co-infect a host, the possibility for recombination arises, though the dynamics of recombination are unexplored. Here I investigated the extent of recombination in laboratory reared pupae of Apis mellifera and Bombus terrestris. Ten pupae of B. terrestris and 10 of A. mellifera were co-infected with DWV-A and DWV-B (105 genome equivalents per bee) and incubated for three days for the viruses to replicate. Virus was extracted from these 3-day-old pupae then used to infect new pupae. This was repeated nine times, producing ten independent lines of virus passaged through naïve B. terrestris and A. mellifera pupae. RNA was extracted, DNA generated from it by cDNA synthesis, and the DNA used in qPCRs to quantify viral replication in all replicates. To determine if recombination had occurred, primers were used to amplify recombinant DWV-A/DWV-B across the VP3-helicase genes and results compared across the two host species. The IVA (Interactive Virus Assembly) program was also used to see which recombinants dominated in the genome. BLAST analysis allowed me to assign DWV (as DWV-A, DWV-B or DWV-AB-recombinant) sequences within the consensus sequences created by an IVA de novo assembly. These results support the idea that recombinants have a growth advantage over parental genotypes.