Table 2.
Examples of genes duplicated in the blue whale
| Gene (human ortholog) | Description (human ortholog) | Number of copies | Comments | |||
|---|---|---|---|---|---|---|
| Blue whale | Vaquita | Bottlenose dolphin | Cattle | |||
| C2orf78 | Chromosome 2 Open Reading Frame 78 | 150 | 3 | 4 | 1 | Uncharacterized protein. Allelic and copy number variants and a genomic rearrangement linked to cancers (Park et al. 2012; Jaratlerdsiri et al. 2017; Xicola et al. 2018). Apparent copy number in the blue whale may be affected by proximity to a centromere. |
| MT1A/MT1X | Metallothionein | 53 | 7 | 1 | 1 | Sequesters toxic metals, linked to longevity and cancer (Goulding et al. 1995; Pedersen et al. 2009; Sigel et al. 2015; Pabis et al. 2021). |
| MTRNR2L5 | MT-RNR2 like 5 (pseudogene) | 41 | 5 | 12 | 14 | Humanin-like: a member of a large family of micropeptides encoded by nuclear paralogs of the mitochondrial MT-RNR2 gene. |
| DPEP2 | Dipeptidase 2 | 32 | 3 | 3 | 1 | Linked to body size (Deciphering Developmental Disorders Study 2015), obesity and diabetes (Liu et al. 2013; Heemskerk et al. 2015; Sárvári et al. 2021), Alzheimer's disease (Carlyle et al. 2022), cancer, immunity, and inflammation (Yang et al. 2019; Rao et al. 2021; Huang et al. 2022; Han et al. 2023) |
| FZD5 | Frizzled 5 | 17 | 1 | 1 | 1 | A member of the WNT signaling pathway, involved in development, regeneration, and cancer (Bhanot et al. 1996; Yang-Snyder et al. 1996; He et al. 1997; Shulman et al. 1998; Ishikawa et al. 2001; Huang and Klein 2004; Burns et al. 2008; Thiele et al. 2018; Sun et al. 2020; Dong et al. 2021) |
| DDX24 | DEAD-box helicase 24 | 14 | 1 | 1 | 1 | An RNA helicase involved in RNA virus-host interactions and cancer (Ma et al. 2008: 24; Ma et al. 2013: 24; Shi et al. 2016: 24) |
| NCAM1 (also known as CD56) | Neural cell adhesion molecule 1 | 15 | 1 | 1 | 1 | Nervous and immune systems, blood cancers (Atz et al. 2007: 1; Alegretti et al. 2011: 56; Vukojevic et al. 2020; Jennings et al. 2022: 1) |
| KCNMB1 | Potassium calcium-activated channel subfamily M regulatory beta subunit 1 | 12 | 1 | 1 | 1 | Linked to hypertension (Sentí et al. 2005: 1; Kelley-Hedgepeth et al. 2008: 1; Grimm et al. 2009: 1) |
| XRCC1 | X-ray repair cross-complementing protein 1 | 2 | 1 | 1 | 1 | Plays an important role in DNA damage repair, associated with several human cancers (Tebbs et al. 1999; Schneider et al. 2008; Hanssen-Bauer et al. 2012; Wang and Ai 2014; Ghosh et al. 2016; Meng et al. 2017; Wu et al. 2020; Demin et al. 2021; Gong et al. 2021; Tang and Çağlayan 2021). |
| CDK20 | Cyclin-dependent kinase 20 | 4 | 1 | 1 | 1 | A key regulator of the cell cycle, involved in mammalian development and cancer (Snouffer et al. 2017; Lai et al. 2020). |
| CHRNB1 | Cholinergic receptor nicotinic beta 1 subunit | 2 | 2 | 3 | 1 | Linked to body size traits in sheep, BMI in humans. and congenital myasthenic syndromes that affect neuromuscular transmission (Müller et al. 2007; Kominakis et al. 2017; Zhao et al. 2021). The second copy has pseudogenized in vaquita. |
This is a subset of genes listed in supplementary table S4, Supplementary Material online, chosen for large copy numbers in blue whale, copy number differences between blue whale and vaquita, and/or potential relevance to body size and longevity traits.