Research & Initiatives

Overview of Ruminant T2T Consortium

Timothy P.L. Smith, Brenda M. Murdoch, Benjamin D. Rosen, and Stephanie D. McKay

The first draft human genome assembly was released over twenty years ago, but a gapless
telomere to telomere (T2T) “complete” assembly was elusive until last year. The highly
repetitive nature of the pericentromeric, subtelomeric and duplicated gene families such as the
rRNA arrays made them impossible to assemble until advances in long read sequencing
technologies, coupled with new bioinformatic tools, resolved these structures. We recently
proposed application of these new resources, tools and knowledge in support of a “Ruminant
T2T Consortium” with the goal of generating complete genomes for the ruminant evolutionary
lineage.

The ruminant Suborder is represented by six Families and 66 living genera, found in
geographically dispersed areas, adapted to a wide variety of environments, and subjected to both
natural and artificial selection. Our hypothesis is that generating T2T assemblies of ruminant
species with a resolution from closely related (e.g. capable of interbreeding, even if only
generating sterile offspring) to higher evolutionary distance (up to the estimated 25 million
years ago last common ancestor) will inform our understanding of the underpinnings of
ruminant evolution, shed light on the genomic consequences of domestication, and enhance
our knowledge of the functional roles of heterochromatin and other repeat regions of the
genome.

A ruminant T2T workshop, held in February at the USDA Meat and Animal Research Center in
Nebraska, featured presentations from the founders of the human T2T effort and leaders of the
vertebrate genomes and earth biogenome projects to provide details of their experience and lend
assistance in designing/optimizing the project. The consortium developed working groups to
conduct orthogonal data production and analyses. The working groups include Chromosome
Evolution, 3D Genome Architecture, Comparative Methylome, Assemblers and Curation,
Annotation, Variant Discovery and population sequencing, Immunome analyses, Cytogenetic.
This update is intended to share the outcomes of the ruminant T2T workshop and provide an
opportunity for interested members of the International Genomes community to participate.