Dates are a familiar sight for NYU Abu Dhabi students. Dates can be a sweet study snack and a great present to bring home for the holidays. But how do you know which dates to get for your sweet-toothed cousin or your grandmother who prefers redder fruits over yellower ones? A team of researchers from the Center for Genomics and Systems Biology at NYUAD in collaboration with researchers from United Arab Emirates University has been working on understanding the intricacies of the date palm – phoenix dactylifera – genome and its correlative physical characteristics using samples from two farms in the UAE.

Their recently published article in Nature Communications outlines an improved date palm genome assembly which they used to find the sex-determining region of DNA and to conduct genome-wide association studies for 21 fruit traits. GWAS is an approach that is widely used by geneticists to help identify mutations in the sequence that are correlated with specific traits. Scientists can record physical traits like sugar content, size and moisture content for a particular individual and pair these observations with the genetic sequence of that individual. Using computational methods, geneticists can look at correlations between certain genetic determinants and characteristics. GWAS allows researchers to look at many different genetic determinants at once, which is particularly helpful in understanding the genetic basis behind complex traits that are determined by more than one mutation or gene.

A genome is the full set of genetic information in an organism or individual. Each cell of an organism has the same genetic sequence, which serves as an instruction manual for the proteins that must be synthesized for proper functioning and identity of the organism. Understanding the genetic sequence of a species can provide insight into the evolution and history of the species as well as what makes the species distinct.

The team focused on fruit color and sugar content as significant GWAS traits that could be explained by genetic variation in samples. One gene was identified for the determination of color in date palms. The VIRESCENS gene was previously identified by the group as an important player in the date palm coloration, but this paper shows the sequence of the gene in full and explores the functional effect of the retrotransposon mutation that is responsible for a loss of red color. A retrotransposon is a bit of genetic material also known as a “jumping gene” that can amplify its own presence in the genome. The research team named the retrotransposon in the VIRESCENS gene Ibn Majid after the 15th century Arab navigator from the UAE. This gene is just one example of the type of information that can be extracted from the genome with the team’s robust data and computational methods.

The research has vast implications for the understanding of the date palm genome due to its long relationship with humans through domestication, its widespread cultural significance and its ability to thrive in relatively harsh climates. There is archeological evidence from Dalma Island that shows date stones associated with human settlements from the late sixth to early fifth millennia B.C. This ancient historical connection between one of the first domesticated tree crops and the Arabian Gulf region is significant because as the only indigenous crop of the Arabian Peninsula, the date palm’s genome may hold information about the people who first domesticated it. Genomics researchers can examine mutation rates and similarities in single nucleotide polymorphisms and correlate this data with location and time period to understand how dates⁠ – often through the hands of humans – moved and evolved with time. This data can inform studies of trade and cultural exchanges.

Dates are also a key focus in studies of food security in light of our changing climate. The date palm is well adapted to a type of oasis agriculture that allows for areas with limited water supply to successfully grow the crop. Moreover, varieties of date palms from the eastern part of the Indian subcontinent exist in North Africa, parts of sub-Saharan Africa as well as the Middle East. In this way, an understanding of the date palm genome and the way it functions in stressful environments will be helpful for people hoping to start agricultural practices in dry areas.

Hopefully, these innovations will allow for a better understanding of domestication and how it influences evolution, the people of early civilizations and their relationship with food and with one another, possible options for food security in an unpredictable climate and of course, how to choose the best date.