Effect of Temperature and Parental Age on Fecundity and Offspring Fitness

Nicole Acosta Author

04/05/2021 Added

6 Plays

Description

The elder the parents and the higher the temperature the less fitness offspring in Drosophila melanogaster flies.

Searchable Transcript

Search:

[00:00:01.260]Hi. My name is Nicole Acosta.
[00:00:01.700]I am a biochemistry senior and today I am going to talk
[00:00:04.800]about my UCARE project,
[00:00:06.150]which is about the effect of temperature and parental age on fecundity and offspring
[00:00:10.410]fitness. So I have been working with Dr. Montooth ... with Dr.
[00:00:15.000]Montooth at her lab for over a year and a half.
[00:00:19.250]I always wanted to know all the data we collect is then turned into graphs
[00:00:24.080], and curves.
[00:00:25.670]And all of these figures are then used
[00:00:30.620]to do predictions and all of this.
[00:00:33.830]So I wanted to know more about the process. Um,
[00:00:36.680]this is one of the reasons why I decided to do my project in, in this area.
[00:00:41.570]So we worked with Drosophila melanogaster flies. These are ectothers,
[00:00:45.650]meaning they cannot regulate their own body temperature.
[00:00:48.620]They depend on the environmental temperature since global warming is,
[00:00:53.720]um, altering the mean and variance of environment temperature,
[00:00:58.790]this place will be affected by that. So, yep. At the right.
[00:01:03.770]You can see a thermal performance curve,
[00:01:06.380]and this is a quantitative way to measure the effects of temperature on flies.
[00:01:10.070]So there are three important things about this graph.
[00:01:13.580]The first one is the temperature optimum,
[00:01:16.190]which is the temperature of which flies will best perform. The breath,
[00:01:19.880]temperature breathd, and the criticals minimum and maximum temperature.
[00:01:25.280]My objectives.
[00:01:26.420]The first one is to evaluate reproductive fitness in response to a thermal
[00:01:29.270]environment under a wide range of contant temperatures.
[00:01:31.600]Second one model thermal performance curves of reproductive fitness. And determine
[00:01:36.380]the effect of age of female fecundity.
[00:01:39.850]Assess impacts of parental age on offspring development survivorship.
[00:01:43.370]Analyze interaction between parental age and temperature on the reproduction
[00:01:47.510]and offspring developmentl survivorship. Methods are divided into two.
[00:01:52.460]The first part is experimental design and the data collection.
[00:01:55.670]And the second part is the analysis of the data. So the,
[00:01:59.990]so for the main population, uh,
[00:02:04.880]flies were cut from here, Lincoln, Nebraska, okay. The,
[00:02:09.850]the flights were kept at 22 degrees Celsius.
[00:02:12.470]Each generation of newly emerged flights were reared in plastic bottles to keep
[00:02:16.580]an breeding population and genetic variation, cohorts from different bottles were
[00:02:21.470]mixed every generation.
[00:02:21.740]After 12 generations, flies from this main population were
[00:02:26.570]kept into egg collection cages with agar plates. Flies,
[00:02:30.590]lay the eggs in the agar plates, and we can easily collect the eggs.
[00:02:35.300]So we collect 30 eggs and place them on a new agar plate.
[00:02:41.210]And these eggs were kept at a determined temperature,
[00:02:45.830]as you can see in the diagram.
[00:02:48.350]So we have four cohort per temperature, and each cohort,
[00:02:55.130]have 30 eggs.
[00:03:00.040]Eggs were kept until the emerged to adults. And once they are,
[00:03:03.670]they were adult we kept a female and three males on the same vial.
[00:03:08.860]We transferred them, the flies, every day. Uh, the old vial,
[00:03:13.390]we come to the eggs and we kept the via until
[00:03:19.770]the adults emerged.
[00:03:21.270]We count the females and we count the males that emerged
[00:03:26.280]from these eggs.
[00:03:28.770]This is part of the experimental design. So for the analysis,
[00:03:33.420]we modeled the TPC curve of female reproductive fitness using the nonlinear
[00:03:38.100]thermodynamic pross-based model Sharpe.
[00:03:41.910]We with the TPC group with TPC,
[00:03:44.640]we determine the optimum temperature, standard breathd,
[00:03:48.660]tolerance rates range, and activation energy.
[00:03:52.140]We also analyze temperature by age interaction effects on reproduction
[00:03:57.120]using different types of regression included linear model,
[00:04:00.360]linear mixed models, generalized linear model and generalized lineal mixed model.
[00:04:06.300]So for results here, you can see that eggs, uh,
[00:04:11.160]eggs offspring, the eggs and the adults, uh, different temperatures.
[00:04:15.060]As you can see, 22 where the flies that lay more eggs,
[00:04:17.940]as well as they flies that produce more adults, uh,
[00:04:22.920]31 eggs are about 300. However, that is,
[00:04:25.980]you cannot see that much of adults are temperature 31,
[00:04:31.260]meaning the, there is a high mortality between eggs and adults at this,
[00:04:35.940]uh, temperature. Here you can see the thermal performance gear that you can see,
[00:04:41.340]temperature optimum is 23.4, four eggs and 23.2 for adults.
[00:04:46.530]Um, the temperature breathd, which is, uh, at,
[00:04:50.640]in this case is 80,
[00:04:52.710]meaning that this is the temperature range at which 80%
[00:04:57.510]of the population will succeed for eggs
[00:05:02.460]eggs, which is, uh, on your left.
[00:05:04.770]It is between 18.5 and 26.8 degrees Celsius.
[00:05:08.850]And for adults, which is, and you're right,
[00:05:11.760]it is between 18.5 and 25.9.
[00:05:16.740]And temperature critical temperatures are
[00:05:21.240]6.8 to 34.8,
[00:05:24.270]for eggs. And 9.1 and
[00:05:28.110]32.0 for adults.
[00:05:32.490]So this will be their range at which they will, uh,
[00:05:35.700]the critical minimum and maximum for this flies.
[00:05:41.130]So here we see the relationship between number of offspring and parental
[00:05:45.930]age, as well as temperature. So you can see here,
[00:05:49.620]there is a lot of eggs
[00:05:55.110]At high temperatures, females lay more eggs. However,
[00:05:59.570]they have a shorter lifespan, as you can see here as well. Um,
[00:06:04.550]the lower, the temperature, the longer the lifespan. Uh,
[00:06:07.760]we also notice that the
[00:06:11.450]at 17.5 degrees Celsius,
[00:06:13.610]they have a higher reproductive output that at 16 degrees Celsius, uh,
[00:06:17.960]even the 16 is a lower temperature than, 17.5. So, um,
[00:06:22.580]These are the important, um, important parts parts of these graphs.
[00:06:28.160]Here, we see the average survivorship,
[00:06:31.940]as you can see at 18 was when
[00:06:34.660]the
[00:06:39.160]the survivorship was higher. At 31
[00:06:41.380]it was lower as we already see also in the first set of results in
[00:06:46.300]the right.
[00:06:46.660]You see that 17.5 was the temperature that
[00:06:51.490]has the higher survivorship. And, uh,
[00:06:56.110]at higher temperatures like 22, sorry,
[00:06:58.650]28 and 25 parents did not.
[00:07:02.680]Parents have short lifespan and, uh,
[00:07:05.200]they have not had as high survivorship as lower temperatures.
[00:07:09.460]Here we have linear mixed models and generalized linear mixed models for
[00:07:14.020]a eggs. As you can see,
[00:07:16.450]16 have a longer lifespan for both graphs
[00:07:21.520]and the higher, the temperature, the shorter, the lifespan,
[00:07:25.660]In conclusion,
[00:07:26.560]environmental conditions like temperature, shape the relationship between parental age
[00:07:30.220]and offspring fitness. So we know about the relationship.
[00:07:33.730]We know that the older the parents, fewer eggs. The higher
[00:07:37.900]the temperature fewer eggs, but we don't know why.
[00:07:41.620]So that will be a good area for research for future
[00:07:47.140]uh, investigations. Uh, thank you. Thank you Dr. Montooth, Dr.
[00:07:51.550]Roston and Dr. Ibrahim, for being part of this process.

The screen size you are trying to search captions on is too small!

You can always jump over to MediaHub and check it out there.

Comments

0 Comments

Effect of Temperature and Parental Age on Fecundity and Offspring Fitness

Description

Searchable Transcript

Comments icon comment

Related Channels

Comments