Jeff Groh
@jeffgroh.bsky.social
Postdoc at UC Berkeley | evolutionary genetics & genomics, plant mating systems, hybridization
Pinned
Balanced polymorphism in a floral transcription factor underlies an ancient rhythm of daily sex alternation in avocado
In avocado and certain wild relatives in Lauraceae, pollination occurs via a synchronized rhythm of floral sex timing between two hermaphroditic flowering types. A-type plants present female-phase flo...
www.biorxiv.org
Did you know there are 2 types of avocado varieties? A-types switch from female to male, B-types male to female, within a single day. This reciprocal sex alternation promotes cross-pollination and has a simple genetic basis. Read more in this recent preprint from the final chapter of my PhD thesis 🥑
Reposted by Jeff Groh
… Bernie Sanders statement: “Donald Trump has, once again, shown his contempt for the Constitution and the rule of law….”
January 3, 2026 at 5:58 PM
… Bernie Sanders statement: “Donald Trump has, once again, shown his contempt for the Constitution and the rule of law….”
Did you know there are 2 types of avocado varieties? A-types switch from female to male, B-types male to female, within a single day. This reciprocal sex alternation promotes cross-pollination and has a simple genetic basis. Read more in this recent preprint from the final chapter of my PhD thesis 🥑
Balanced polymorphism in a floral transcription factor underlies an ancient rhythm of daily sex alternation in avocado
In avocado and certain wild relatives in Lauraceae, pollination occurs via a synchronized rhythm of floral sex timing between two hermaphroditic flowering types. A-type plants present female-phase flo...
www.biorxiv.org
December 29, 2025 at 7:13 PM
Did you know there are 2 types of avocado varieties? A-types switch from female to male, B-types male to female, within a single day. This reciprocal sex alternation promotes cross-pollination and has a simple genetic basis. Read more in this recent preprint from the final chapter of my PhD thesis 🥑
Reposted by Jeff Groh
Congrats @jeffgroh.bsky.social et al. Some avocado trees open female-phase flowers in the morning & then male in afternoon. Others show complementary pattern (m->f), to synchronize pollination of two types. Jeff show this to be a >45Mya polymorphism at a transcription factor across 100s of species.
Balanced polymorphism in a floral transcription factor underlies an ancient rhythm of daily sex alternation in avocado https://www.biorxiv.org/content/10.64898/2025.12.22.695989v1
December 25, 2025 at 6:47 PM
Congrats @jeffgroh.bsky.social et al. Some avocado trees open female-phase flowers in the morning & then male in afternoon. Others show complementary pattern (m->f), to synchronize pollination of two types. Jeff show this to be a >45Mya polymorphism at a transcription factor across 100s of species.
Reposted by Jeff Groh
I’ll never look at avocados in quite the same way: The latest from UC Berkeley Miller Fellow Jeff Groh who sits in my lab and Ben Blackman’s lab. He works on balancing selection and molecular mechanisms underlying the coevolutionary phenomenon of mating type alternation (PhD with Graham Koop).
Balanced polymorphism in a floral transcription factor underlies an ancient rhythm of daily sex alternation in avocado https://www.biorxiv.org/content/10.64898/2025.12.22.695989v1
December 25, 2025 at 3:23 PM
I’ll never look at avocados in quite the same way: The latest from UC Berkeley Miller Fellow Jeff Groh who sits in my lab and Ben Blackman’s lab. He works on balancing selection and molecular mechanisms underlying the coevolutionary phenomenon of mating type alternation (PhD with Graham Koop).
Reposted by Jeff Groh
Very excited to share the capstone of my postdoc work with @stepheniwright.bsky.social, co-led by Wright lab grad student Cassandre with contributions from many others.
We combined new methods with high-quality Rumex assemblies to dive into the remarkable history of rearrangement in this genus.
We combined new methods with high-quality Rumex assemblies to dive into the remarkable history of rearrangement in this genus.
Rapid evolution of synteny associated with multiple origins of dioecy and XY sex determination
Chromosomal rearrangements are a major driver of evolutionary innovation, shaping processes including local adaptation, speciation, and sex chromosome evolution. Multispecies synteny datasets are rich...
www.biorxiv.org
December 23, 2025 at 4:53 PM
Very excited to share the capstone of my postdoc work with @stepheniwright.bsky.social, co-led by Wright lab grad student Cassandre with contributions from many others.
We combined new methods with high-quality Rumex assemblies to dive into the remarkable history of rearrangement in this genus.
We combined new methods with high-quality Rumex assemblies to dive into the remarkable history of rearrangement in this genus.
Reposted by Jeff Groh
🧬 Just out in Bioinformatics Advances: “tskit arg visualizer: Interactive plotting of ancestral recombination graphs.”
Read the full paper here: https://doi.org/10.1093/bioadv/vbaf302
Authors include: @kitchensjn.bsky.social, @yanwong.bsky.social
Read the full paper here: https://doi.org/10.1093/bioadv/vbaf302
Authors include: @kitchensjn.bsky.social, @yanwong.bsky.social
December 18, 2025 at 10:02 AM
🧬 Just out in Bioinformatics Advances: “tskit arg visualizer: Interactive plotting of ancestral recombination graphs.”
Read the full paper here: https://doi.org/10.1093/bioadv/vbaf302
Authors include: @kitchensjn.bsky.social, @yanwong.bsky.social
Read the full paper here: https://doi.org/10.1093/bioadv/vbaf302
Authors include: @kitchensjn.bsky.social, @yanwong.bsky.social
Reposted by Jeff Groh
I am currently searching for a new postdoctoral researcher to study the evolution, genetics, and physiology of cold acclimation and freezing tolerance in switchgrass at Michigan State University. This work will be funded by a newly funded five-year DOE grant. careers.msu.edu/jobs/researc...
Research Associate-Fixed Term - East Lansing, Michigan, United States
Position Summary
The Lowry Lab at Michigan State University is searching for a postdoctoral research associate to conduct molecular and physiological experiments to understand the causes of genetic va...
careers.msu.edu
November 20, 2025 at 2:50 PM
I am currently searching for a new postdoctoral researcher to study the evolution, genetics, and physiology of cold acclimation and freezing tolerance in switchgrass at Michigan State University. This work will be funded by a newly funded five-year DOE grant. careers.msu.edu/jobs/researc...
Reposted by Jeff Groh
With @aconga.bsky.social we wrote a short Dispatch to highlight two awesome companion papers in @currentbiology.bsky.social by @jeffgroh.bsky.social, @gcbias.bsky.social and by Liu et al. on how the control of heterodichogamy is going nuts in the Juglandaceae :
www.cell.com/current-biol...
www.cell.com/current-biol...
November 5, 2025 at 8:00 AM
With @aconga.bsky.social we wrote a short Dispatch to highlight two awesome companion papers in @currentbiology.bsky.social by @jeffgroh.bsky.social, @gcbias.bsky.social and by Liu et al. on how the control of heterodichogamy is going nuts in the Juglandaceae :
www.cell.com/current-biol...
www.cell.com/current-biol...
Reposted by Jeff Groh
Hermaphroditic plants also use TIME ⏰🌿 to avoid selfing.
Two new @currentbiology.bsky.social papers explore the rapid turnover of this trait in the wingnut family.
Both @vincentcastric.bsky.social and I summarized these findings 👉 authors.elsevier.com/a/1m2MA3QW8S...
#Evolution #PlantBiology
Two new @currentbiology.bsky.social papers explore the rapid turnover of this trait in the wingnut family.
Both @vincentcastric.bsky.social and I summarized these findings 👉 authors.elsevier.com/a/1m2MA3QW8S...
#Evolution #PlantBiology
November 4, 2025 at 7:30 PM
Hermaphroditic plants also use TIME ⏰🌿 to avoid selfing.
Two new @currentbiology.bsky.social papers explore the rapid turnover of this trait in the wingnut family.
Both @vincentcastric.bsky.social and I summarized these findings 👉 authors.elsevier.com/a/1m2MA3QW8S...
#Evolution #PlantBiology
Two new @currentbiology.bsky.social papers explore the rapid turnover of this trait in the wingnut family.
Both @vincentcastric.bsky.social and I summarized these findings 👉 authors.elsevier.com/a/1m2MA3QW8S...
#Evolution #PlantBiology
Reposted by Jeff Groh
Congratulations to @jeffgroh.bsky.social on the publication of his paper on an ancient balanced polymorphisms controlling heterodichogamy in two genera of wingnuts. The paper shows the putative turnover & reversal of dominance of a mating type polymorphism
www.sciencedirect.com/science/arti...
www.sciencedirect.com/science/arti...
Distinct haplotypes and reversed dominance at a single-gene balanced polymorphism controlling heterodichogamy in two genera of wingnuts
In the angiosperm mating system of heterodichogamy, two hermaphroditic morphs temporally alternate between male and female flowering phases, promoting…
www.sciencedirect.com
October 16, 2025 at 3:42 PM
Congratulations to @jeffgroh.bsky.social on the publication of his paper on an ancient balanced polymorphisms controlling heterodichogamy in two genera of wingnuts. The paper shows the putative turnover & reversal of dominance of a mating type polymorphism
www.sciencedirect.com/science/arti...
www.sciencedirect.com/science/arti...
Sharing our new paper, "Distinct haplotypes and reversed dominance at a single-gene balanced polymorphism controlling heterodichogamy in two genera of wingnuts". Genomics & evolution of a mating type system involving two morphs with alternating sexes in walnut relatives www.cell.com/current-biol...
Distinct haplotypes and reversed dominance at a single-gene balanced polymorphism controlling heterodichogamy in two genera of wingnuts
In most species within the walnut family, two genetically determined morphs alternate
between male and female flowering phases in time. Groh et al. identify a distinct
locus for this dimorphism in two...
www.cell.com
October 16, 2025 at 3:43 PM
Sharing our new paper, "Distinct haplotypes and reversed dominance at a single-gene balanced polymorphism controlling heterodichogamy in two genera of wingnuts". Genomics & evolution of a mating type system involving two morphs with alternating sexes in walnut relatives www.cell.com/current-biol...
Reposted by Jeff Groh
We're excited to be recruiting an NIH funded postdoc to work in the Coop lab at UC Davis. We're specifically interested in candidates who are want to work at the intersection of human genetics, GWAS, and population genetics modeling. Please RT
October 15, 2025 at 3:53 PM
We're excited to be recruiting an NIH funded postdoc to work in the Coop lab at UC Davis. We're specifically interested in candidates who are want to work at the intersection of human genetics, GWAS, and population genetics modeling. Please RT
Work led by Marius Roesti, "A species interaction kick-starts ecological speciation in allopatry" now published - Varying degrees of divergence associated with presence/absence of a single interacting species predicts strength of prezygotic RI in freshwater stickleback www.pnas.org/doi/10.1073/...
A species interaction kick-starts ecological speciation in allopatry | PNAS
Adaptation to different environments is thought to play a key role in speciation.
However, speciation typically begins in allopatry, where reproduc...
www.pnas.org
October 14, 2025 at 2:12 AM
Work led by Marius Roesti, "A species interaction kick-starts ecological speciation in allopatry" now published - Varying degrees of divergence associated with presence/absence of a single interacting species predicts strength of prezygotic RI in freshwater stickleback www.pnas.org/doi/10.1073/...
Reposted by Jeff Groh
New Article: "Ginger genome reveals the SMPED1 gene causing sex-phase synchrony and outcrossing in a flowering plant" rdcu.be/eJPdX
SMPED1, located in a dichogamy-determining region in Alpinia species, controls the timing of sex-organ synchrony.
SMPED1, located in a dichogamy-determining region in Alpinia species, controls the timing of sex-organ synchrony.
October 7, 2025 at 11:07 AM
New Article: "Ginger genome reveals the SMPED1 gene causing sex-phase synchrony and outcrossing in a flowering plant" rdcu.be/eJPdX
SMPED1, located in a dichogamy-determining region in Alpinia species, controls the timing of sex-organ synchrony.
SMPED1, located in a dichogamy-determining region in Alpinia species, controls the timing of sex-organ synchrony.
Reposted by Jeff Groh
Quantitative system drift https://www.biorxiv.org/content/10.1101/2025.09.17.676933v1
September 20, 2025 at 4:32 PM
Quantitative system drift https://www.biorxiv.org/content/10.1101/2025.09.17.676933v1
Reposted by Jeff Groh
Please share broadly: I am looking for a postdoctoral fellow to work on a collaborative project on the temporal population genomics of invasive Capeweed (using contemporary and herbarium genomics), with @shaky-dingo.bsky.social and colleagues
August 27, 2025 at 12:09 PM
Please share broadly: I am looking for a postdoctoral fellow to work on a collaborative project on the temporal population genomics of invasive Capeweed (using contemporary and herbarium genomics), with @shaky-dingo.bsky.social and colleagues
Reposted by Jeff Groh
Excited to share our new preprint for the tskit_arg_visualizer Python package! ARGs can sometimes feel like a black box, so
@yanwong.bsky.social and I have been developing a method to programmatically drawing these graphs.
🔗 arxiv.org/abs/2508.03958
1/6
@yanwong.bsky.social and I have been developing a method to programmatically drawing these graphs.
🔗 arxiv.org/abs/2508.03958
1/6
tskit_arg_visualizer: interactive plotting of ancestral recombination graphs
Summary: Ancestral recombination graphs (ARGs) are a complete representation of the genetic relationships between recombining lineages and are of central importance in population genetics. Recent brea...
arxiv.org
August 19, 2025 at 2:12 PM
Excited to share our new preprint for the tskit_arg_visualizer Python package! ARGs can sometimes feel like a black box, so
@yanwong.bsky.social and I have been developing a method to programmatically drawing these graphs.
🔗 arxiv.org/abs/2508.03958
1/6
@yanwong.bsky.social and I have been developing a method to programmatically drawing these graphs.
🔗 arxiv.org/abs/2508.03958
1/6
Reposted by Jeff Groh
Fields like Computer Science, Physics/Astronomy, and Chemistry saw the largest increases in NSF GRFP awards in 2025.
Meanwhile, Life Sciences, Social Sciences, Psychology, and Mathematical Sciences experienced the steepest declines—marking a major departure from historical funding patterns.
Meanwhile, Life Sciences, Social Sciences, Psychology, and Mathematical Sciences experienced the steepest declines—marking a major departure from historical funding patterns.
June 26, 2025 at 4:32 PM
Fields like Computer Science, Physics/Astronomy, and Chemistry saw the largest increases in NSF GRFP awards in 2025.
Meanwhile, Life Sciences, Social Sciences, Psychology, and Mathematical Sciences experienced the steepest declines—marking a major departure from historical funding patterns.
Meanwhile, Life Sciences, Social Sciences, Psychology, and Mathematical Sciences experienced the steepest declines—marking a major departure from historical funding patterns.
Looking forward to #Evol2025! I’ll be presenting on the genetics of a balanced polymorphism for sex timing in hermaphroditic plants in the Reproductive Systems session on June 22 at 11:15 AM
June 20, 2025 at 12:09 AM
Looking forward to #Evol2025! I’ll be presenting on the genetics of a balanced polymorphism for sex timing in hermaphroditic plants in the Reproductive Systems session on June 22 at 11:15 AM
Reposted by Jeff Groh
How bad will it be? Catastrophic.
Proposed cuts to #NSF, #NIH, and #NASA will set the US R&D landscape back 25 yrs+, cause economic and job loss now, and undermine innovations to come.
But, this is the WH's *proposed* budget.
Speak up now before it is too late.
(inflation adjusted $-s below)
Proposed cuts to #NSF, #NIH, and #NASA will set the US R&D landscape back 25 yrs+, cause economic and job loss now, and undermine innovations to come.
But, this is the WH's *proposed* budget.
Speak up now before it is too late.
(inflation adjusted $-s below)
May 31, 2025 at 2:50 AM
Reposted by Jeff Groh
1/9 Excited to share the preprint for the second half of my PhD with @mollyschumer.bsky.social: Connecting human environmental impacts to hybridization in swordtail fish through genomics, GIS, water chemistry, and histology. Thread below!
#SciSky
www.biorxiv.org/content/10.1...
#SciSky
www.biorxiv.org/content/10.1...
Increased rates of hybridization in swordtail fish are associated with water pollution
Biodiversity loss can occur when disturbance compromises the reproductive barriers between species, causing them to collapse into a single population through hybridization. Recent research has documen...
www.biorxiv.org
May 1, 2025 at 1:15 PM
1/9 Excited to share the preprint for the second half of my PhD with @mollyschumer.bsky.social: Connecting human environmental impacts to hybridization in swordtail fish through genomics, GIS, water chemistry, and histology. Thread below!
#SciSky
www.biorxiv.org/content/10.1...
#SciSky
www.biorxiv.org/content/10.1...
Congrats to my wonderful PhD advisor @gcbias.bsky.social on being elected to American Academy of Arts & Sciences! www.amacad.org/new-members-...
New Academy Members
Elected in 2025
www.amacad.org
April 24, 2025 at 4:58 PM
Congrats to my wonderful PhD advisor @gcbias.bsky.social on being elected to American Academy of Arts & Sciences! www.amacad.org/new-members-...
Reposted by Jeff Groh
Biologist Jeff Groh wrote home to Hummelstown PA 🚜 to lay out the many costs of cuts to American science infrastructure. “Let’s not ruin a good thing” 🧪🏠
Inspired by others on here I wrote a short op-ed in support of federal research funding for a local newspaper in small town PA where I grew up
April 10, 2025 at 8:39 PM
Biologist Jeff Groh wrote home to Hummelstown PA 🚜 to lay out the many costs of cuts to American science infrastructure. “Let’s not ruin a good thing” 🧪🏠
Inspired by others on here I wrote a short op-ed in support of federal research funding for a local newspaper in small town PA where I grew up
April 10, 2025 at 8:19 PM
Inspired by others on here I wrote a short op-ed in support of federal research funding for a local newspaper in small town PA where I grew up
Reposted by Jeff Groh
More than 1,200 demonstrations were held across the country on Saturday against the policies and actions of President Donald Trump and Elon Musk. See images from some of the protests in California, Florida, Washington, D.C., and more.
Photos: Nationwide Protests Against Trump and Musk
Images from some of the hundreds of anti-Trump demonstrations across the country.
bit.ly
April 6, 2025 at 8:15 PM
More than 1,200 demonstrations were held across the country on Saturday against the policies and actions of President Donald Trump and Elon Musk. See images from some of the protests in California, Florida, Washington, D.C., and more.