YSM Issue 90.4

in brief
NEWS
The Twists and Turns of Flowers
By Ashwin Chetty
Have you ever taken time to enjoy the
beauty of flowers? Professor Vivian Irish and
postdoctoral associate Adam Saffer of Yale’s
Molecular, Cellular and Developmental
Biology department have done so for years,
especially from a scientific perspective.
They study what affects a flower’s shape
and appearance. Recently, they discovered
a molecule that affects the twist of flowers,
which refers to the way flowers turn. In
their Current Biology paper published in
August, they revealed that in a specific type
of flower, Arabidopsis thaliana, a substance
called pectin influences the twisting of plant
cells. Pectin is a common substance in the
kitchen and gives jam its gelatinous quality.
Saffer first looked at a mutation that caused
plant cells to be short and twisted. The
researchers then identified a mutated gene
underlying the helical shape of these cells.
This gene plays a role in the biosynthesis
of a certain kind of pectin called RG-
I. The researchers believe that RG-I may
normally counteract a component of cell
walls that causes cells to twist. However,
when the mutation is present in a cell, less
RG-I is is produced. RG-I inhibits twisting,
so when RG-I levels are low, the unknown
component is free to make cells twist. Thus,
the mutation causes the beautiful helical
shape of plant cells.
The Irish Lab is working to better
understand the role of pectin in providing
cell structure, and Irish is partnering
with researchers at Yale’s department of
mechanical engineering and materials
science to develop models to explain this
left-handed twisting. By identifying a novel
characteristic of pectin, Irish and Saffer
have opened doors for the development of
new biomaterials. While they are excited
for these applications, at the end of the
day, both still like to enjoy the aesthetically
pleasing nature of flowers.
PHOTO BY TANVI MEHTA
►Pectin, the substance that gives jam
its gelatinous quality, can influence the
way that flowers twist.
Raising a child is no easy task—what
would you do if you were put in charge of
raising someone else’s child? In a recent
study, researchers from the Yale Department
of Ecology and Evolutionary Biology
explored whether males of different animal
species would care for offspring that aren’t
their own. The researchers studied how the
energy needed to raise a child could affect
males’ decisions to care for offspring.
Previous theories state that males are most
likely to care for children that are certain to
be their own. Yet in many species, a male
may take care of offspring that were not
conceived by him but rather by a competing
male. Postdoctoral research fellow Gustavo
Requena explained the difference between
his model and those of earlier theories. “In
our study, we used mathematical models
to emulate males’ decisions in different
scenarios and ultimately address the same
question but took into account a more
general biological reality,” he said. This
Game of Sperms
By Lauren Kim
model involves sperm competition games,
which show how males allocate energetic
resources to increase their chances
for success within male-male mating
competition.
Factors that affect the males’ decisions
include female promiscuity, maternal
effort, and the difficulty of providing
care to offspring. Based on these factors,
researchers found that when there is more
energy required, males will provide care
based on relatedness to his offspring. For
example, a male Arowana fish will carry
eggs in his mouth to protect his offspring.
However, in low-cost situations, males will
provide care regardless of relation.
In this way, scientists hope to provide
an answer as to why males continue to
provide energetically-costly care towards
offspring that may not be their own. From
these results, they can develop a greater
understanding of different parenting
patterns in nature.
IMAGE COURTESY OF NATIONAL GEOGRAPHIC
►Male Arowana fish carry the eggs in
their mouths, protecting the offspring
until they are ready to leave permanently.
www.yalescientific.org
October 2017
Yale Scientific Magazine
7