[4] They elucidated the mechanism of induction of yeast metallothionein by copper ions,[5] one of the first eukaryotic gene regulatory systems to be understood at the molecular level and a useful method for regulating therapeutic protein production.
His research group's first paper, published in Science in 1993, reported that the maternal but not paternal male relatives of gay men had increased rates of same-sex orientation, suggesting the possibility of sex-linked transmission in a portion of the population.
The authors concluded that "our findings, taken in context with previous work, suggest that genetic variation in each of these regions contributes to development of the important psychological trait of male sexual orientation."
This study was questioned on account of its reliance on a dichotomous ever/never measure that lumped together predominantly heterosexual, bisexual and homosexual individuals, including those who only experimented once with a same-sex partner, possibly resulting in misleading associations to personality traits.
[15] Hamer's findings provoked extensive public reaction, often based on misunderstanding of the science, which led to his interest in explaining the data to a wide audience through a book written in collaboration with a journalist.
[17] Hamer and colleagues also investigated the genetic roots of anxiety and found that a promoter region polymorphism in the gene for the serotonin transporter, which is the target of antidepressant drugs such as Prozac, is associated with mood and personality.
By genetically engineering normal vaginal bacteria to produce a potent anti-HIV peptide, significant protection against viral infection was provided in a durable and obtainable fashion for up to one month.
Their feature documentary Kumu Hina, about transgender native Hawaiian teacher and cultural icon Hinaleimoana Wong-Kalu, was supported by ITVS, Pacific Islanders in Communications and the Ford Foundation and won the GLAAD Media Award for Outstanding Documentary and the Independent Lens Audience Award on PBS[30] In 2017, Hamer and Wilson, with Hinaleimoana Wong-Kalu as producer, released Leitis in Waiting and Lady Eva, which documented the lives of transgender women in the conservative South Pacific Kingdom of Tonga.
Hamer, Wilson and Wong-Kalu continued their collaboration in 2020 with the animated short film Kapaemahu, based on the hidden history of four stones on Waikiki Beach placed there as a tribute to four legendary mahu who first brought the healing arts from Tahiti to Hawaii.
The animated film was followed by a children's book published by Kokila,[33] a PBS feature documentary,[34] a multimedia exhibition at the Bishop Museum,[35] permanent display at the Hawai'i Convention center,[36] and inclusion in new interpretative signage at the Kapaemahu monument in Waikiki.