gene insertion article 56 nonhuman 52 controlled study 40 priority journal 36 female 30 Animals 28 Female 24 male 22 Mutation 20 Male 18 gene mutation 18 genetic variability 18 genetic analysis 16 genetics 16 Drosophila melanogaster 14 Humans 14 Mice 14 animal cell 14 gene 14 human 14 nucleotide sequence 14 phenotype 14 bacterial gene 12 gene deletion 12 gene expression 12 gene expression regulation 12 heterozygosity 12 promoter region 12 temperature 12