Required for the formation of N(7)-methylguanine at position 46 (m7G46) in tRNA. In the complex, it is required to stabilize and induce conformational changes of the catalytic subunit. Required during gametogenesis. tRNA modification; N(7)-methylguanine-tRNA biosynthesis. Forms a heterodimer with the catalytic subunit. Localized to the nuclei of nurse cells, follicle cells and oocytes at early stages, from germarium to stage 4 egg chambers. Also present in the nuclei of spermatocytes and in the apical cells of the testes. In testis, it is present at high level in hub cells, a niche for germline stem cells of testis. Male sterile and female semi-sterile phenotypes. In males, spermatogenesis is arrested at the elongating stage of the developing spermatids, resulting in an absence of mature sperms in the seminal vesicles. The decreased fertility in females is mostly due to defects in oogenesis. There are abnormal egg chambers present in the mutant females, in which the cystocytes fail to arrest their cell division at the fourth mitotic cycle, resulting in more than 16 cells in a single egg chamber. Additionally, these abnormal cystocytes do not undergo multiple rounds of endoreplication as the nurse cells do in a normal egg chamber. Wuho means 'no progeny' in Chinese. Belongs to the WD repeat TRM82 family. Duplication of 82 nt that changes the frame.