1
00:00:11,340 --> 00:00:09,520
yes so today I'd like to talk to you

2
00:00:15,070 --> 00:00:11,350
guys about some of the molecular

3
00:00:16,750 --> 00:00:15,080
adaptations to life in very cool

4
00:00:18,580 --> 00:00:16,760
environments and I'm going to

5
00:00:21,370 --> 00:00:18,590
specifically talk about a bacteria that

6
00:00:25,420 --> 00:00:21,380
we've isolated recently in my laboratory

7
00:00:27,159 --> 00:00:25,430
called panic caucus hello craft 'less so

8
00:00:29,530 --> 00:00:27,169
just to give a little bit of background

9
00:00:32,650 --> 00:00:29,540
most of the work in my laboratory is

10
00:00:34,510 --> 00:00:32,660
done in the Arctic or with microbial

11
00:00:36,819 --> 00:00:34,520
habitats and or microbes that live in

12
00:00:39,250 --> 00:00:36,829
the Arctic so there are a number of

13
00:00:43,750 --> 00:00:39,260
unique microbial habitats that we find

14
00:00:47,110 --> 00:00:43,760
there they include hyper saline Springs

15
00:00:49,150 --> 00:00:47,120
permafrost and crypto endelis which you

16
00:00:50,650 --> 00:00:49,160
maybe can tell jackie was having a hard

17
00:00:52,900 --> 00:00:50,660
time earlier but you can see maybe the

18
00:00:56,610 --> 00:00:52,910
green layer there which is basically

19
00:00:59,500 --> 00:00:56,620
made up of microb microbes so these

20
00:01:01,239 --> 00:00:59,510
habitats are also pretty good

21
00:01:03,639 --> 00:01:01,249
terrestrial analogs for certain places

22
00:01:08,740 --> 00:01:03,649
in our solar system that's our kind of

23
00:01:10,060 --> 00:01:08,750
cold frozen or salty but they're also

24
00:01:11,980 --> 00:01:10,070
really good places for the study of

25
00:01:15,880 --> 00:01:11,990
profiles or extremophiles that like

26
00:01:18,550 --> 00:01:15,890
really really cold environments so just

27
00:01:20,830 --> 00:01:18,560
to situate you a little bit this is us

28
00:01:23,139 --> 00:01:20,840
somewhere right around here and if you

29
00:01:24,999 --> 00:01:23,149
enlarge this area up here this is

30
00:01:26,410 --> 00:01:25,009
ellesmere island and axel Heiberg island

31
00:01:28,929 --> 00:01:26,420
and a lot of the research the design in

32
00:01:30,130 --> 00:01:28,939
my lab is done here and plan a caucus

33
00:01:32,160 --> 00:01:30,140
the bacteria that I'm going to talk

34
00:01:37,870 --> 00:01:32,170
about was actually isolated from this

35
00:01:40,810 --> 00:01:37,880
region here Eureka none of it so plan a

36
00:01:42,160 --> 00:01:40,820
caucus hell Acropolis is really cool

37
00:01:43,660 --> 00:01:42,170
really interesting because it actually

38
00:01:45,550 --> 00:01:43,670
grows at the lowest temperature that

39
00:01:48,789 --> 00:01:45,560
we've ever recorded to date which is

40
00:01:50,800 --> 00:01:48,799
minus 15 degrees Celsius and it also

41
00:01:53,859 --> 00:01:50,810
tolerates up to nineteen percent salt

42
00:01:56,020 --> 00:01:53,869
which is very high this is a scanning

43
00:01:58,209 --> 00:01:56,030
electron micrograph of planet caucus so

44
00:01:59,770 --> 00:01:58,219
it's a typical guy I meaning that's

45
00:02:02,529 --> 00:01:59,780
round and diplo meaning that it usually

46
00:02:08,169 --> 00:02:02,539
lives with another another one of itself

47
00:02:09,490 --> 00:02:08,179
joined together so most of the work then

48
00:02:10,840 --> 00:02:09,500
I'm pretty much all the work that I'm

49
00:02:14,470 --> 00:02:10,850
going to present today is actually from

50
00:02:17,650 --> 00:02:14,480
an ex post doc in my laboratory her name

51
00:02:18,660 --> 00:02:17,660
is Nadia Nick mikha Chuck and so she

52
00:02:20,370 --> 00:02:18,670
isolated

53
00:02:23,760 --> 00:02:20,380
bacteria and then did a bunch of work

54
00:02:25,589 --> 00:02:23,770
looking at the molecular the molecular

55
00:02:27,809 --> 00:02:25,599
adaptations of this organism so she

56
00:02:29,790 --> 00:02:27,819
looked at genomic trade she basically

57
00:02:31,290 --> 00:02:29,800
sequenced the whole genome she looked at

58
00:02:33,300 --> 00:02:31,300
the trends she did transcriptomic

59
00:02:35,940 --> 00:02:33,310
analysis which is basically looking at

60
00:02:38,460 --> 00:02:35,950
are comparing which genes are active in

61
00:02:40,170 --> 00:02:38,470
certain conditions compared to four

62
00:02:42,090 --> 00:02:40,180
extra which teams are actually for

63
00:02:43,830 --> 00:02:42,100
example at room temperature compared to

64
00:02:46,680 --> 00:02:43,840
Regine's are active at minus 15 degrees

65
00:02:48,780 --> 00:02:46,690
Celsius but one of the first things that

66
00:02:50,699 --> 00:02:48,790
she did is she looked to the bacteria

67
00:02:52,710 --> 00:02:50,709
under the microscope so these are

68
00:02:54,449 --> 00:02:52,720
scanning electron micrographs and she

69
00:02:57,270 --> 00:02:54,459
compared what they look like at

70
00:02:59,190 --> 00:02:57,280
different temperatures so this up here

71
00:03:01,920 --> 00:02:59,200
is 25 degrees Celsius and this is what

72
00:03:03,090 --> 00:03:01,930
Victoria usually look like this is what

73
00:03:05,309 --> 00:03:03,100
we see in this is what planet caucus

74
00:03:07,710 --> 00:03:05,319
usually looks like 25 when you look at

75
00:03:09,660 --> 00:03:07,720
it at minus-5 you can see that it starts

76
00:03:11,580 --> 00:03:09,670
to change a little bit the surface looks

77
00:03:13,740 --> 00:03:11,590
a little bit more different not sure

78
00:03:15,660 --> 00:03:13,750
what's going on but it's you but it

79
00:03:17,940 --> 00:03:15,670
looks a little strange when you go to

80
00:03:20,309 --> 00:03:17,950
minus-15 it looks completely different

81
00:03:22,800 --> 00:03:20,319
so something is happening to the surface

82
00:03:25,199 --> 00:03:22,810
of the bacteria minus 15 degrees Celsius

83
00:03:26,789 --> 00:03:25,209
now i wish i could tell you like that we

84
00:03:28,470 --> 00:03:26,799
know exactly what's going on that we

85
00:03:30,960 --> 00:03:28,480
know exactly what this is and the reason

86
00:03:32,729 --> 00:03:30,970
why it's there but we don't we're

87
00:03:34,860 --> 00:03:32,739
looking into that right now jen is

88
00:03:36,300 --> 00:03:34,870
actually looking into maybe what this is

89
00:03:39,270 --> 00:03:36,310
composed of and the reason why this

90
00:03:41,759 --> 00:03:39,280
envelope is there it's there's a few

91
00:03:43,020 --> 00:03:41,769
different possibilities it could be a

92
00:03:46,440 --> 00:03:43,030
mixture of different things it could be

93
00:03:49,380 --> 00:03:46,450
proteins lipids maybe biofilm of some

94
00:03:52,590 --> 00:03:49,390
sort it could be just residue from cell

95
00:03:55,020 --> 00:03:52,600
wall when the bacteria separates where

96
00:03:57,720 --> 00:03:55,030
where the actual separation when the

97
00:04:00,690 --> 00:03:57,730
vector replicates where that happens it

98
00:04:03,059 --> 00:04:00,700
could be just extra cell membrane that

99
00:04:05,690 --> 00:04:03,069
is just left there but we don't really

100
00:04:08,069 --> 00:04:05,700
know right now exactly what's going on

101
00:04:11,250 --> 00:04:08,079
so the next thing that not you did after

102
00:04:13,080 --> 00:04:11,260
she looked at at added under the

103
00:04:14,940 --> 00:04:13,090
microscope is she basically did she

104
00:04:17,930 --> 00:04:14,950
sequence the entire genome and then she

105
00:04:21,000 --> 00:04:17,940
analyzed the genome for essentially

106
00:04:23,190 --> 00:04:21,010
adaptations that she could find for life

107
00:04:25,260 --> 00:04:23,200
in cold environments and one of the

108
00:04:27,180 --> 00:04:25,270
things that she found is this is what we

109
00:04:31,790 --> 00:04:27,190
call genomic plasticity and so it's this

110
00:04:33,830 --> 00:04:31,800
idea that organisms like conical

111
00:04:36,830 --> 00:04:33,840
this organisms that that live in really

112
00:04:38,510 --> 00:04:36,840
cold or stressful environments have many

113
00:04:39,980 --> 00:04:38,520
copies of the same genes so they

114
00:04:42,200 --> 00:04:39,990
basically have many versions of the same

115
00:04:44,839 --> 00:04:42,210
gene and the reason why they do this is

116
00:04:46,430 --> 00:04:44,849
this basically allows them to survive in

117
00:04:49,040 --> 00:04:46,440
these in these in many different

118
00:04:51,439 --> 00:04:49,050
stressful conditions so for example in a

119
00:04:53,659 --> 00:04:51,449
warmer or a salt condition you might use

120
00:04:55,309 --> 00:04:53,669
one version of a gene whereas in another

121
00:04:56,990 --> 00:04:55,319
condition like a colder condition you'll

122
00:04:58,219 --> 00:04:57,000
use another version of a gene so

123
00:05:00,320 --> 00:04:58,229
depending on which condition you're in

124
00:05:01,999 --> 00:05:00,330
which stress you have you're going to be

125
00:05:04,430 --> 00:05:02,009
using a different version of the same

126
00:05:06,680 --> 00:05:04,440
gene and each version is a little bit

127
00:05:08,779 --> 00:05:06,690
different and it allows you it allows

128
00:05:09,950 --> 00:05:08,789
the organism to use that same gene but

129
00:05:11,899 --> 00:05:09,960
in these different environmental

130
00:05:14,059 --> 00:05:11,909
stressors so you can see for plan or

131
00:05:16,369 --> 00:05:14,069
caucus for example this is looking at

132
00:05:18,110 --> 00:05:16,379
choline betaine uptake so this is

133
00:05:20,089 --> 00:05:18,120
looking at solute I've taken synthesis

134
00:05:22,159 --> 00:05:20,099
and solute is really important for the

135
00:05:24,350 --> 00:05:22,169
bacteria in order to allow it to survive

136
00:05:26,240 --> 00:05:24,360
in really high salt conditions so it

137
00:05:28,129 --> 00:05:26,250
accumulates these solutes these little

138
00:05:30,170 --> 00:05:28,139
organic molecules inside the cell and

139
00:05:32,300 --> 00:05:30,180
they actually allow it to survive

140
00:05:34,760 --> 00:05:32,310
eighteen nineteen percent salt and

141
00:05:36,200 --> 00:05:34,770
really high salt percentages and so if

142
00:05:38,390 --> 00:05:36,210
you look at just these genes that are

143
00:05:40,159 --> 00:05:38,400
involved in this process final caucus

144
00:05:42,499 --> 00:05:40,169
has a lot of them and has many copies of

145
00:05:43,820 --> 00:05:42,509
these genes so it's just idea then that

146
00:05:46,700 --> 00:05:43,830
depending on the environment will find

147
00:05:49,129 --> 00:05:46,710
itself in it can up-regulate one version

148
00:05:50,990 --> 00:05:49,139
of the same gene whichever one is

149
00:05:53,529 --> 00:05:51,000
necessary for the environment that it's

150
00:05:56,600 --> 00:05:53,539
in so the other thing that she looked at

151
00:05:59,409 --> 00:05:56,610
was the idea of or she looked at amino

152
00:06:03,290 --> 00:05:59,419
acid changes so you have a gene sequence

153
00:06:05,390 --> 00:06:03,300
and cold-adapted proteins will actually

154
00:06:08,209 --> 00:06:05,400
change so essentially if you take a gene

155
00:06:10,249 --> 00:06:08,219
your gene codes for amino acids which

156
00:06:12,170 --> 00:06:10,259
then make a protein and which amino

157
00:06:15,760 --> 00:06:12,180
acids are in that protein can actually

158
00:06:20,029 --> 00:06:15,770
change and so this is the idea of

159
00:06:23,330 --> 00:06:20,039
increasing protein flexibility so if you

160
00:06:25,279 --> 00:06:23,340
look at at these like these to hear what

161
00:06:28,129 --> 00:06:25,289
she essentially found is most of the

162
00:06:30,800 --> 00:06:28,139
genes in panto caucus actually have less

163
00:06:32,959 --> 00:06:30,810
acidic and proline residues so they're

164
00:06:34,430 --> 00:06:32,969
basically cold-adapted because having

165
00:06:36,529 --> 00:06:34,440
less of these gives you increased

166
00:06:39,430 --> 00:06:36,539
protein flexibility so a lot of these

167
00:06:43,879 --> 00:06:39,440
genes are essentially better adapted to

168
00:06:49,999 --> 00:06:48,110
on oops so the next thing that she did

169
00:06:52,010 --> 00:06:50,009
was then transcriptomic analysis she

170
00:06:55,339 --> 00:06:52,020
basically looks at looked at which genes

171
00:06:57,920 --> 00:06:55,349
were active at minus 15 and which genes

172
00:06:59,420 --> 00:06:57,930
were active at a high-salt in which

173
00:07:00,679 --> 00:06:59,430
genes were active at room temperature

174
00:07:03,080 --> 00:07:00,689
and then she compared them to

175
00:07:06,260 --> 00:07:03,090
essentially get a better idea of which

176
00:07:08,830 --> 00:07:06,270
processes inside the cell were were

177
00:07:13,369 --> 00:07:08,840
involved in high salt or minus 15

178
00:07:15,230 --> 00:07:13,379
conditions so the main thing that she

179
00:07:16,550 --> 00:07:15,240
found are these are essentially two of

180
00:07:18,830 --> 00:07:16,560
the main things that she found which is

181
00:07:20,269 --> 00:07:18,840
one there's decreased expression across

182
00:07:22,159 --> 00:07:20,279
functional categories and that just

183
00:07:24,050 --> 00:07:22,169
basically means that in general the

184
00:07:25,580 --> 00:07:24,060
bacteria shuts down most processes that

185
00:07:26,659 --> 00:07:25,590
aren't necessary so a lot of genes that

186
00:07:28,219 --> 00:07:26,669
aren't necessarily they're not going to

187
00:07:30,080 --> 00:07:28,229
be active you don't want to waste energy

188
00:07:33,290 --> 00:07:30,090
having a lot of things active that you

189
00:07:35,209 --> 00:07:33,300
don't need to have so most cellular

190
00:07:37,040 --> 00:07:35,219
functions are repressed but she did find

191
00:07:39,439 --> 00:07:37,050
upregulation of a number of genes

192
00:07:40,850 --> 00:07:39,449
involved in cell wall modifications

193
00:07:43,459 --> 00:07:40,860
which we can expect based on the

194
00:07:45,950 --> 00:07:43,469
pictures that we saw earlier amino acid

195
00:07:47,510 --> 00:07:45,960
metabolism as well as oxidative stress

196
00:07:49,640 --> 00:07:47,520
response which is normal when you're

197
00:07:51,170 --> 00:07:49,650
under stress and changes in

198
00:07:52,790 --> 00:07:51,180
transcriptional regulation or a lot of

199
00:07:55,999 --> 00:07:52,800
transcription transcriptional regulation

200
00:07:59,719 --> 00:07:56,009
so again you can easily shut on and off

201
00:08:01,579 --> 00:07:59,729
genes that you need or don't need so

202
00:08:03,579 --> 00:08:01,589
this is the last picture that I want to

203
00:08:06,499 --> 00:08:03,589
show you guys which kind of looks really

204
00:08:08,510 --> 00:08:06,509
confusing and complicated it's not

205
00:08:12,559 --> 00:08:08,520
really well as a sort of this is

206
00:08:14,510 --> 00:08:12,569
basically a very it is but it's it's

207
00:08:16,610 --> 00:08:14,520
basically a very brief overview of all

208
00:08:18,529 --> 00:08:16,620
of the different processes that are

209
00:08:21,200 --> 00:08:18,539
happening at any single time inside of

210
00:08:22,369 --> 00:08:21,210
self and that's even not even nearly

211
00:08:25,879 --> 00:08:22,379
close to everything that's happening

212
00:08:27,649 --> 00:08:25,889
inside of a cell but in terms of town of

213
00:08:30,050 --> 00:08:27,659
chacas what we want to highlight are

214
00:08:32,509 --> 00:08:30,060
basically the genome encoded adaptations

215
00:08:35,389 --> 00:08:32,519
cold adaptations that Nadia found to be

216
00:08:37,670 --> 00:08:35,399
important and so this is just generally

217
00:08:39,589 --> 00:08:37,680
all the main sort of categories of gene

218
00:08:42,409 --> 00:08:39,599
of adaptations that she found in the

219
00:08:44,360 --> 00:08:42,419
genome so she found adaptations in cold

220
00:08:46,490 --> 00:08:44,370
shop genes or cold shock proteins which

221
00:08:48,500 --> 00:08:46,500
would make sense compatible solute

222
00:08:50,509 --> 00:08:48,510
uptake cell envelope modification and

223
00:08:53,569 --> 00:08:50,519
things of that nature but she did find

224
00:08:56,389 --> 00:08:53,579
that some processes were induced more

225
00:08:57,570 --> 00:08:56,399
either by high salt or more by cold and

226
00:09:00,240 --> 00:08:57,580
so these are highlighted

227
00:09:02,910 --> 00:09:00,250
here so things like lipid synthesis and

228
00:09:05,130 --> 00:09:02,920
turnover amino acid turnover oxidative

229
00:09:07,260 --> 00:09:05,140
stress these seem to be more induced by

230
00:09:10,110 --> 00:09:07,270
the high salt conditions and in the

231
00:09:12,540 --> 00:09:10,120
minus 15 conditions she found again

232
00:09:13,740 --> 00:09:12,550
translation transcription and what I

233
00:09:15,960 --> 00:09:13,750
find really interesting which are these

234
00:09:17,430 --> 00:09:15,970
hypothetical proteins so these are

235
00:09:18,840 --> 00:09:17,440
essentially proteins that we've never

236
00:09:20,220 --> 00:09:18,850
characterized before and that actually

237
00:09:23,700 --> 00:09:20,230
might be really really important for

238
00:09:25,020 --> 00:09:23,710
cold survival but we just don't know

239
00:09:26,430 --> 00:09:25,030
what they do because we've never seen

240
00:09:27,990 --> 00:09:26,440
them before and so I think that's one

241
00:09:30,060 --> 00:09:28,000
area of research in the future that'd be

242
00:09:32,010 --> 00:09:30,070
really interesting which is to look into

243
00:09:34,500 --> 00:09:32,020
what these proteins are and what's their

244
00:09:38,880 --> 00:09:34,510
role in cold survival because they may

245
00:09:41,990 --> 00:09:38,890
be really interesting so the current

246
00:09:44,010 --> 00:09:42,000
work that is going on in our laboratory

247
00:09:45,420 --> 00:09:44,020
involves looking at the composition of

248
00:09:47,940 --> 00:09:45,430
the minus 15 envelope which I mentioned

249
00:09:50,880 --> 00:09:47,950
with jen is looking into we're also

250
00:09:52,560 --> 00:09:50,890
doing some proteomics looking at so the

251
00:09:53,940 --> 00:09:52,570
next steps we look to genes we looked at

252
00:09:55,050 --> 00:09:53,950
which genes are active in which aren't

253
00:09:56,940 --> 00:09:55,060
and then we actually want to look at the

254
00:09:58,800 --> 00:09:56,950
proteins inside the cells and figure out

255
00:09:59,970 --> 00:09:58,810
what's actually going on in terms of the

256
00:10:02,820 --> 00:09:59,980
proteins in terms of the molecular

257
00:10:04,500 --> 00:10:02,830
mechanisms inside the cell and then also

258
00:10:06,540 --> 00:10:04,510
looking at compatible solute so figuring

259
00:10:08,760 --> 00:10:06,550
out how planet caucus is actually able

260
00:10:10,860 --> 00:10:08,770
to tolerate such high salt what which

261
00:10:14,270 --> 00:10:10,870
saw what solute sit actually accumulates

262
00:10:26,700 --> 00:10:14,280
inside the cell for salt tolerance and

263
00:10:28,470 --> 00:10:26,710
that's it so questions for Isabel have

264
00:10:30,210 --> 00:10:28,480
you thought of like over expressing some

265
00:10:32,150 --> 00:10:30,220
of these proteins and like e.coli or

266
00:10:34,740 --> 00:10:32,160
something and seeing if they enable

267
00:10:37,230 --> 00:10:34,750
maybe I called education medical

268
00:10:40,140 --> 00:10:37,240
proteins well more you could

269
00:10:42,300 --> 00:10:40,150
hypothetical but more safely some of the

270
00:10:43,770 --> 00:10:42,310
ones that affect like the lipid membrane

271
00:10:45,360 --> 00:10:43,780
and stuff like that oh yeah for sure

272
00:10:47,010 --> 00:10:45,370
that's there's so many things that you

273
00:10:49,260 --> 00:10:47,020
can do with the organism at this point

274
00:10:50,940 --> 00:10:49,270
yeah um and so we're just at the

275
00:11:01,680 --> 00:10:50,950
beginning of looking at this more but

276
00:11:07,450 --> 00:11:04,780
it was my turn our online turn is your

277
00:11:08,950 --> 00:11:07,460
organism genetically tractable what do

278
00:11:10,510 --> 00:11:08,960
you mean by tonight sorry I mean are you

279
00:11:12,970 --> 00:11:10,520
able to do genetics with your organism

280
00:11:15,400 --> 00:11:12,980
like meat make mutants with it wow you

281
00:11:17,110 --> 00:11:15,410
sure you could okay I was just wondering

282
00:11:18,610 --> 00:11:17,120
if your lab also makes mutants with the

283
00:11:20,170 --> 00:11:18,620
organism to investigate like the

284
00:11:22,000 --> 00:11:20,180
function of like the hypothetical

285
00:11:27,579 --> 00:11:22,010
proteins oh yeah no we haven't done that

286
00:11:35,940 --> 00:11:27,589
yet but we definitely could okay cool so

287
00:11:40,810 --> 00:11:38,740
okay this is from batoul our first

288
00:11:44,320 --> 00:11:40,820
question is why is protein flexibility

289
00:11:47,310 --> 00:11:44,330
beneficial in cold environments and so I

290
00:11:50,740 --> 00:11:47,320
guess this is sort of the idea that that

291
00:11:52,600 --> 00:11:50,750
with the cold you want to have proteins

292
00:11:54,880 --> 00:11:52,610
that are very flexible it's easier to

293
00:11:56,769 --> 00:11:54,890
buy into your substrate if you're not so

294
00:11:58,150 --> 00:11:56,779
rigid which is probably what's going to

295
00:12:00,430 --> 00:11:58,160
happen at lower temperatures so

296
00:12:03,670 --> 00:12:00,440
something like prolene creates kinks and

297
00:12:05,470 --> 00:12:03,680
rigidity in an amino acid so you want to

298
00:12:07,240 --> 00:12:05,480
have you rather not have that so that

299
00:12:09,160 --> 00:12:07,250
you're more flexible and when you have

300
00:12:10,750 --> 00:12:09,170
the cold which tends to kind of wants to

301
00:12:14,380 --> 00:12:10,760
slow you down and essentially allows you

302
00:12:16,510 --> 00:12:14,390
to better bind to your substrate okay

303
00:12:18,370 --> 00:12:16,520
and our second one is could you tell

304
00:12:23,820 --> 00:12:18,380
which proteins involved in cell wall

305
00:12:28,180 --> 00:12:26,110
could you tell which proteins involved

306
00:12:31,930 --> 00:12:28,190
in cell wall membrane regulation are

307
00:12:32,740 --> 00:12:31,940
adapted you mean cold-adapted or I don't

308
00:12:34,150 --> 00:12:32,750
think we've looked into that

309
00:12:35,230 --> 00:12:34,160
specifically but that's definitely

310
00:12:36,760 --> 00:12:35,240
something that that we're gonna look